Z/28 Head swap DIY!!!

[BJJKRIS]

So before we get started i need to stress that this DIY owes everything to others before me that have taken the time to create instructional’s/how to’s/DIY’s. Without the info they took the time to compile for us, I never even would’ve attempted this project on my own. Massive thanks to jeffreystar aka sakudog over at the corvetteforums, because his is the one that got me through this. Below is his tutorial and it was massively helpful. And if you read it you will see a lot of similarities (kinda hard not to with both cars running the same engine)

https://www.corvetteforum.com/forums...adswap-11.html

But the reason behind this tutorial is that there isn’t a z/28 specific “how to” for replacing the heads. There’s a great one for the z06, a few good videos on YouTube for the SS camaro and another good zo6 video. And while those will get you through the bulk of the work, i realize other individuals aren’t as mechanically inclined or don’t want to take the chance due to not knowing exactly what to do. The fact that they’re not exactly the same procedure can throw some people off. This is for you guys. And also I hope there is a little more stuff in here that we can all take away and if you have anything to add as well please do!

Difficulty:
6/10. 8/10 if you’re impatient or try to rush. I am not an ASE Certified mechanic by any means, but I’ve worked on Gatling guns and missiles for 13 years and I haven’t blown myself up yet. (Fire controlman. Like a gunners mate but better/smarter/more handsome) So if you can follow directions and pay attention to detail you can handle this without a catastrophic failure.

Total time:
I used the Naval Station Mayport auto skills shop where I have access to a lift and most of the tools you’d ever need. But they have working hours that left me with just a few hours each day to do the work. So 1 week total spread out over 5 working days.... all in all around 15-20 hours total labor time.

Tools:
metric and standard socket set with all the extensions and deep wells
15mm gear wrench (one that swivels is even nicer)
Assorted screw drivers or bits for a cordless impact. Small flat heads come in handy for removal of some connectors.
needle nose pliers (the long angled type preferably)
big breaker bar (head bolts need some torque to get them off)
2 torque wrenches (one for inch, one for up to 90ft lb)
A nice cordless impact gun. I used my cheap Ryobi to make removal of the smaller nuts and bolts go faster.
And also a 90° air ratchet was a life saver when removing the exhaust manifold bolts and removing/re-installing new head bolts (just getting them snug. Not for final torque obviously.)

Parts/materials:
New heads (I used AHP package 4 heads, moldstar90 guides, ferrea hollow exhaust valves, polished titanium intake valves, psi 1511 springs, no porting, and minimally resurfaced the mating surface.
AHP also sells a great install kit that comes with everything you need to do the job. You can try to price it out piece by piece in an effort to save money. But for the price... I couldn’t. I tried. But if you must...
New LS7 MLS head gaskets.
New (recommended not required) exhaust manifold gaskets (these are z/28 specific. We use a different exhaust manifold than the zo6)
New GM head bolts or ARP Studs/Bolts. I used ARP bolts due to the ease of install. Studs if you wanna go forced induction or NOS.
ARP thread chase to clean out the holes for the head bolts. They will have crud in them. But in a pinch you can make your own with an angle grinder and one of the old head bolts.
Freeze/steam plugs. Depending on your head supplier you may get heads with the rear steam ports blocked off as intended in the z/28. (Mine from AHP were blocked off which makes them left/right specific) if you get heads bare you may need to add these yourself.
ARP super lube
Anti seize/thread sealer (used for rocker bolts)
Latex gloves
About 50 sandwich bags
Sharpie
3-5 razor blades
1500grit sandpaper (apparently you can use the white 3m roloc finger style discs for removing head gasket material. Even GM approves of this method but I didn’t like the idea of removing too much metal by accident and end up with a messed up block.)
2 cans of brake cleaner
Can of acetone or isopropyl alcohol
Some straws and a shopvac for cleaning debris from small nooks and crannies and for sucking coolant out of bolt holes.
Access to compressed air
Jack/jack stands or if you’re lucky like me, a lift. (I used a drive on lift with some long 2x6’s as ramps)
Duct tape
Painters tape/towels/fender protectors. Don’t want to drop tools/parts on your fenders. I used the fender protectors with magnets and hooks. Got them off amazon for cheap.
Dexcool coolant
Oil and an oil filter/great time to upgrade to magnetic drain plugs as well.
Second set of eyes and hands is nice to have. (I actually did everything myself until the coolant fill procedure.)
Patience
Attention to detail
A few days time
***DISCLAIMER***
Everyone has different methods for how they do things. Some tools may go unused or perhaps you have a better way. This is what I used and how I did things and it worked for me. This is in no way a guaranteed easiest or right way. And if you turn your key and your engine explodes... please don’t blame me! Blame the second set of hands/eyes you convinced to help you. He probably dropped a socket in one of your intake ports.

Preliminary: Cold start. Film if you have to, but document your oil pressure, temps as it warms up, sound it makes etc... you’ll need a reference for what is “normal”. Take note of all these things because you’ll want to compare when you start it the first time after the install. Also take multiple pictures from different angles. I took a lot and I wish I took more. Do a video walk around of your engine bay taking note of where all the cable harnesses and hoses connect and their layout. Below is a pic of how my car normally displays oil pressure and temps after about 1 min. The car hadn’t been started in a week. Also is a picture of an unmolested engine bay with correct layout of all wiring harnesses/hoses/connectors. It’s easy to put things back wrong, like say, the fuel line underneath the wiring harness.





Step 1. PICK YOUR WORK LOCATION. Make sure you have ample space for laying out parts, tools and other gear without getting it mixed up or lost. Keeping everything organized goes a long way. Time adds up quick when spending time looking for misplaced 10mm sockets or other small parts. So let’s get the car where it’s okay for it to sit for a while. Your own garage/lift/driveway. Where it can easily be jacked up safely and will remain undisturbed by pets and kids.



Step 2. PROTECTION. Use the painters tape method to completely cover front bumper and front fenders (splitter too if you’re prone to dropping stuff) or use large beach towels or the fender protectors as described above.

Step 3. LETS GET STARTED!!! Pop trunk. Disconnect neg terminal and position where it won’t accidentally come into contact with any metal. Or just wrap some shop rags around end of cable. I left my windows up for the duration of this job. But if you’re going to be opening and closing the doors be careful as the window auto up/down function will be disabled and you risk damaging glass/seals if you slam your door. I recommend against storing all of your parts/tools/materials in the trunk because if you need to hook the battery back up in a hurry... you’re not gonna.

Step 4. DRAIN FLUIDS/DISCONNECT EXHAUST FROM HEADERS. Remove radiator cap to vent. Elevate car. Remove giant underbody tray to access radiator drain petcock and place all bolts/screws in a ziploc bag labeled “underbody tray hardware” not all the bolts are the same so make note of which ones go where. To drain coolant try using your hands but if it’s too tight use the needle noses to loosen, just be careful not to break. (Plastic). If you remove it all the way get ready for a mess. I removed a few threads and allowed approx 3 gallons to drain. In hindsight I should’ve drained more because I had a coolant waterfall when I removed the first head. You can reuse the coolant if you’d like. Just be sure to drain into a clean container and then keep away from your dogs/cats/Marines as it is quite tasty and poisonous. At this point go ahead and disconnect the exhaust at the collectors and place any loose bolts in ziploc bags and label “exhaust bolts”. Remove/disconnect 02 sensors and zip tie out if way. YOU DO NOT HAVE TO DRAIN OIL TO REMOVE HEADS (as long as the car is sitting level you won’t lose any oil when removing the heads.)

Step 5. AIRBOX/INTAKE/HOSES. Put the car back on the ground. Remove engine covers. The intake assembly comes apart with your choice of flat head or 8mm socket on the hose clamps. You do not have to remove the MAF sensor. Just unplug and leave it in the intake tube for safe keeping. Air box comes out after removal of the two 10mm nuts. Just pull up really hard and it’ll pop out. Careful not to let it pop up into your face. Put all loose parts in a bag and label appropriately. At this point go ahead and remove hoses connecting oil reservoir to intake tube as well as the oil reservoir to heads. Take a picture and take note of how it all looks before removing. Label pieces with a piece of painters tape and sharpie.

Step 6. REMOVE STRUT TOWER BRACE. Very easy. 14mm. Bag and label bolts.

Step 7. REMOVE UPPER RADIATOR HOSE. Irritating pinch style clamps. Be careful not to pinch yourself. Remove smaller hose that runs to throttle body and label with a piece of painters tape. In the case of the z/28 you do not have to remove the fans.

Step 8. Remind yourself how lucky you are that you’re not doing this on a zo6. Because at this point you’d be creating new curse words trying to remove the power steering pump (thank you EPS), then alternator. And if you don’t know... the PS pump will drive you insane.

Step 9. SERPENTINE BELT/TENSIONER/PULLEY. Use a 14mm to release pressure from tensioner. Remove belt. Use 15mm to remove 3 bolts holding pulley onto drivers side head. Remove 4 bolt holding cable harness ground. Bag and label. Remove 2x 15mm from tensioner. Bag and label.

Step 10. COIL PACKS. Remove big white connector in middle of coil pack. Take your time and study how it disconnects. Under hood heat will make plastic brittle and prone to breaking. So don’t fight it and risk breaking the connectors. Remove the 10mm bolts holding the coil packs on and bag/label. Coil packs come off as one assembly per side.

Step 11. MANIFOLDS/HEADERS. I have kooks long tubes, so this process may not be the same for you. Mine are held on with 7/16 bolts with lock washers. Remove bolts from outside in pattern if you’re a perfectionist. Then pull off headers. Keep gasket safe if you plan on re-using. Mine were difficult to remove from top or bottom so I just left them in the engine bay to the side of the heads. Supposedly I would’ve had to remove steering shaft to free drivers side. And I didn’t try to remove passenger side. Our engine bays are quite large and this really didn’t affect the process. And of course bag/label all bolts.



Step 12. INTAKE MANIFOLD. On the front and rear corners of both heads there are 15mm bolts that hold a wiring harness ground and also serve to hold harness in place. Remove them and disconnect ground/liberate harness from the heads. There may also be plastic “screws” that hold harness in place. Just carefully pull them out. Now take time to go over the entire harness, disconnect everything carefully. This includes all injectors etc... take your time and don’t break anything. Once free, use zip ties to hold harness away from the heads the best you can so that you have room to work. Careful not to force anything too hard for risk of tearing up the harness. You will realize quickly the drivers side is easier to work on due to less harness being in the way. At this point. Make sure all hoses are disconnected from the throttle body. Ensure all hoses and wires are disconnected from manifold that may attach it to something else. After removing fuel line clip and with a fuel line disconnect tool (3/8) disconnect fuel line from drivers side of manifold. Plug fuel line or allow to drain into container. Keep away from open flame if you make a mess. (I zip tied my fuel line vertically along my hood strut) With an 8mm socket/impact remove all the intake manifold bolts that you can reach. The 2 closest to the firewall are your problem bolts. Use 8mm or 1/4” ratchet wrench to remove. Now use painters tape (I use painters tape because it’s easily removed. Gorilla tape and duct tape is not.) to keep the bolts from falling back down into intake ports as you try to remove manifold. It’s too hard to remove manifold and attempt to hold bolts up at same time. Trust me. In the back of the manifold there is a large brake booster hose. Remove it from the non manifold side. Remove other emissions quick disconnect hose. Tape the hoses together. Lift up and rotate intake manifold assembly in counter clockwise motion as you pull it out. Be careful not to drag the manifold across the heads as you risk tearing your intake seals (bad). Place intake manifold somewhere safe and if it’s going to be a while put some shop rags in the ports to keep bugs and stuff out. Bag and label all intake manifold parts. Remove the steam vent hard line that connects the heads together in the front. 10mm. Bag parts and bolts. Label.

Step 13. VALVE COVERS/VALVE TRAIN. Remove the 4x 10mm bolts that hold the valve covers on (they are captive. No need to bag and label.) The passenger side has the faux oil fill cap. It’s idiot proof. Upon removal note condition of valve cover gasket. If it looks like crap now is a good time to replace gasket. This is maybe the only gasket AHP does not provide with their install kit. I removed mine. Cleaned the inside of valve covers with brake clean, compressed air. Cleaned gaskets and set aside. Get your ziplock bags and sharpie ready. Use a magnet to remove all of the intake valve lash caps from the tips of the valves. Do not use pliers as you will scratch them. If you are re using these on the same exact valves I would keep them organized and put them back exactly where they came from. But if you’re running an all new valve train which is the reason most of us would be doing this in the first place. Just toss them in a bag and label “lash caps”. Now let’s make it easy for us to organize the rest. I’ve seen two pieces of 2x4’s and I personally used cardboard. Drill holes so that it is easy to store/organize your rocker bolts and pushrods. I put each pushrod back in its original spot and orientation but used Michigan racing grade 12 rocker bolts. But if you want to reuse your rocker bolts. Put them back where you removed them. Bag each cylinders rockers and label appropriately. (I upgraded to C.H.E. Bronze bushings while doing this install as well. Below is a link to a video instructional. (Very very easy actually)

https://youtu.be/4PAT2HV_yq4



Step 14. REMOVE THE HEADS! The moment we’ve all been waiting for. Open up your box of ARP bolts. Remove the piece of paper. It has a diagram on it for the order of torquing down the bolts. Break loose (not remove) the bolts in reverse order (15-1). Once broken free now is a great time to use that air ratchet and start backing all the bolts out. Once they’re broken loose the order doesn’t matter that you use for removal. Do not remove the ones at the bottom, closest to the ground, all the way just yet. Leave them threaded in by 5-10 turns and then pull up on the head. Let the coolant waterfall make a huge mess because if you’re like me you didn’t drain enough out of the giant z/28 radiator. Once it’s stopped draining then remove the bolts. This will keep coolant out of the holes and make cleanup easier. Another method is to have someone manning your shopvac or towels to clean all this up as it drains. I found them to just be in the way though. My heads lifted right off with no issue. If you have higher miles you may have a little more difficult time as the MLS Gasket likes to stick. If it does use a plastic prybar to scrape the gasket off the surface to allow you to remove the head from engine bay. Be careful throughout this process to not drop/bang head against block. Don’t want to remove entire block for decking because you let the head slip out of your hands.




Step 15. CLEANING THE MATING SURFACE. The heads use two dowel pins to locate the whole assembly just right. I found it easier to pinch them with a pair of needle noses and remove them to make the cleaning process easier. Don’t lose these. You will notice that the surface is quite disgusting and will more than likely need a fair amount of cleaning. This is one of the more crucial parts of this install. Take your time and don’t get in a rush. Use a razor blade in one hand and shopvac hose in the other. Don’t let the crud fall into the block. Scrape the excess graphite and sludge off best you can. Once you can’t scrape anymore it’s time to hit it with some brake clean and a rag. I have an excess pile of lint free detailing rags so I used like ten of them. Now that it’s wiped down you’ll see what else needs to be touched up. At this point if it can’t be scraped off with a razor it’s time to use the 1500 grit. I sprayed brake clean on the block then went over the whole area with the 1500. A few minutes of this and I was good to go. I’ve seen people use the white roloc discs and make this a 5 min job but it just seems like too much debris flying around for it to be safe. Once it is clean look at it. Pat yourself on the back. And then clean it again. It’s probably still not clean enough.



Step 16. CLEANING THE BOLT HOLES. Air compresses. Water/coolant does not. If you try to put a new bolt in a hole filled with fluid you’re going to crack your block. You can use Q-tips, rolled up paper towels, or compressed air (risk sending stuff flying into places you don’t want.) or you can use this wonderful method pioneered by our good friend sakudog. Tape a 7/11 straw into the mouth of the shopvac hose. This worked great for me. Now that you have your hose contraption built it’s time to really clean these holes. Take your ARP thread chase and your impact or ratchet. I think it was an 8mm i used to turn it. Slowly thread it down into each hole until you feel resistance. Make note of how long your head bolts are so that you know when you’re bottoming out the chase. I put a piece of painters tape on the chase as reference. As you feel resistance, you will remove it then go again. Going a little further every time. This will remove all the old thread sealer from the factory. Once you’re able to thread the chase in easily take your vacuum contraption and suck out all the loose crud from the holes.

Step 17. INSPECT NEW HARDWARE. Make sure we’re putting good parts back on. Look at your heads. Make sure all springs are on correctly. Locks, keepers, retainers etc... make sure everything is in order. Just because a shop across the country built them correctly doesn’t mean the UPS man didn’t drop them 20 feet from a warehouse loading dock. Make sure all mating surfaces are clean and not gouged or scratched. Take your hardware from the old heads (coolant sensor, coolant plug, 15mm ground bolts, steam ports in the back etc...) and put them on the new heads. Inspect all of your new gaskets, bolts etc... install new or old spark plugs.

Step 18. INSTALL NEW HEADS!!! Put on nitrile gloves. With some acetone or isopropyl, use a lint free rag to clean all mating surfaces and new MLS Head gasket. Inspect for lint and dust. I used compressed air to make sure they were dust free. The head gaskets are labeled “FRONT” and are really hard to mess up. Make sure that your lifter trays are installed now because they have to be in before you put the gasket on. Don’t ask how I know. With the gasket on, lower the new head onto block making sure to use aligning dowels to locate head in the precise spot. Use two of the head bolts threaded hand tight to keep everything in place while you take a breather and get ready for the next step.









Step 19. TORQUING NEW HEAD BOLTS. I used my air ratchet to get all of the bolts mostly installed. Not tight at all, but to where I didn’t have to spend an hour with a ratchet. Once they’re all in place it’s time to break out that diagram provided by ARP. It’s pretty self explanatory, just go in order and don’t get mixed up. Don’t want to leave any untouched. Go slow and use a calibrated torque wrench.



Step 20. INSTALL HEADERS. This was way more difficult than I had expected honestly. From the top. Try and pick the header up and get one bolt started. Then it’s a lot easier to position the entire assembly/new gasket to get another one started. Be very careful not to strip these or get them cross threaded. Once they are in you can torque them down starting from the inside moving out. 2 cycles. First cycle 11ft lbs. second cycle 15 ft lbs.

Step 21. VALVE TRAIN. Put your lash caps back on the intake valves (if you’re still running titanium intake valves). One side at a time let’s put some oil on each rocker arm, spring, and rocker. Careful not to get oil in the rocker arm bolt holes. For those you can use thread sealer although they’re blind holes and it’s prob not necessary. Now you can re-install each rocker. Keep in mind the orientation of the rocker. Make sure the rocker arm is in its little pocket and that the valve stem is aligned with the tip of the rocker and not hanging off one side. Torque the bolts to 22ft lbs. This is the easy way of installing the rockers. If you did milling, added a cam, or a thicker head gasket then you’ll need to measure for new rocker arms. The GM procedure btw has you set engine to TDC and torque each rocker in a particular order. That’s okay too obviously. Put valve covers back on.



Step 22. REINSTALL INTAKE MANIFOLD/COILPACKS. Make sure your intake manifold is clean and free of dust and loose debris. I had leaves and a dead grasshopper on mine. Take a rag and isopropyl/acetone and clean the surface of the intake ports on the heads. You want a good seal here. Now on the manifold, inspect the green seals for damage/wear. Clean if necessary. If everything looks good then let’s move on. Pick up the manifold and in a clockwise motion move it towards the firewall swinging it into place carefully. The rear bolts should still be taped up to keep them from getting caught in the intake ports. The brake boost and emissions hose should also be taped together. Now is the time to remove tape. Allow bolts to fall into place and reconnect hoses. Reattach hose clamp on brake boost hose. With a flashlight inspect proper alignment by verifying bolt holes line up from the top. If they do you can start threading these most of the way down. Contemplate removing the name plate of the guy that built your engine at the factory because you just spent hours of your life doing the same thing. Then leave it on the manifold because you didn’t build the bottom end. If you’re replacing heads because you dropped a valve then toss name plate into the ocean. Torque manifold bolts according to diagram. First pass 44in lbs. 2nd pass 89in lbs. reinstall throttle body hardlines. Connect your brake boost and emissions hose in the back. Now start laying out your main engine harness. This is where taking pictures is important. It’s easy to lay harness over fuel line etc... connect harness, make sure all injectors etc are properly connected. Ensure no unnecessary tension is on harness. If it feels like you have to stretch it to get it into place stop and check things out. Should essentially fall into place. Reconnect fuel line and clip. Fasten all the 15mm bolts that hold the harness and grounds in place. Reinstall coil packs. Reconnect spark plug wires. If using MSD red wires like me you will notice they barely have any slack. AHP informed me to make sure they’re twisted right (one end is angled) to make room. Also the socks will help hold the wire in the shape you need.





Step 23. TENSIONER/DRIVERS SIDE PULLEY. Once again count your blessings for not having to deal with zo6 power steering pump and alternator. Reinstall tensioner with its two 15mm bolts. Reinstall drivers side pulley to head with its 3 15mm bolts.

Step 24. RADIATOR HOSE/INTAKE. Reinstall upper radiator hose. Reinstall intake assembly. Connect MAF sensor. Connect all oil catch hoses.

Step 25. Lift car. Reconnect exhaust collectors. Mine are being a pain and not sealing all the way. I can visually see a gap even after they’re clamped down. Time to switch to V band. Lower car off of lift. Here is a pic of the day after the head install getting exhaust leaks fixed.



Step 26. Connect battery. Refill radiator with new dexcool premix or 50/50 mix of distilled water and concentrate and then STOP!!!

Step 27. Look around. Make sure you can account for all tools. All parts. Check engine bay for anything foreign that might be laying around. Check all connectors. Check all bolts that you can see and get to. Read this over again and make sure you didn’t skip a step (after reading this a second time i realized I’d missed a breather hose on the drivers side valve cover, and forgot to put the hose clamp back on the brake booster hose.) Visualize in your mind everything that you’ve done and think of anything you might’ve missed. Sometimes reading the steps will remind you of something. Have someone else that’s knowledgeable look over the engine bay for anything out of line.


Now is a good time to start going over pictures. Compare the before and after. Does everything look the same? Do I have spare bolts? (I had one. And fortunately via troubleshooting why my car wouldn’t start with AHP via Instagram they led me to a disconnected ground on the passenger side front head.)

Step 28. Start the car. If it sounds bad then shut it off. You would know if it’s catastrophic. If it sounds good then gently rev it to 2000rpm’s and hold. Let off then gently rev to 3000rpm’s and hold. Let off. (This procedure is from AHP and to allow oil to get into the valvetrain.) Let idle to normal operating temps and then turn off. Let it cool down. (Heads only require a heat cycle. No need to break in like a new motor.)

Note: For the first start expect a fair amount of steam/smoke once the engine is warmed up. The headers will cook off the coolant, oil, brake clean that you used. While it’s idling for the first minute I put my hand near the manifolds to check for leaks.

Step 29. RE-TORQUE ROCKER BOLTS/RE-TORQUE EXH. MANIFOLD BOLT/STRUT TOWER BAR. Remove coil packs. Get the harness out of the way if necessary. Check torque of exhaust manifold bolts. (Inside to outside, 15 ft lbs) Remove valve covers. Check torque on all 16 rocker bolts (22ft lbs. mine were all still good) and inspect valvetrain for proper alignment. (Rocker tips are on the valve tips and lash caps.) Reattach strut tower brace once you’ve reassembled everything.

Step 30. Just go over your work area. Check again for spare parts, tools etc. check your coolant levels, and depending on how much you drained you may need to do the standard fill procedure. Nothing crazy.

Okay guys that’s it. I know that all of this looks a lot like another well known zo6 how to. That’s because it’s very similar. But I know how it is being afraid to work on something without having proper procedures. Not saying that you couldn’t get through the process with the zo6 version (I did obviously) but it’s nice to not do extra work. So that being said, the differences between the two cars if you’re curious...

We don’t mess with the ABS block, power steering, alternator... we have it easier. Also we can work from the front of the car due to our hood opening conventionally. Although our hood strut gets in the way on the already more difficult drivers side.

What I would’ve done differently?

I would’ve sourced a new set of valve cover gaskets.
Had someone help me from underneath the car hold the exhaust manifolds up while I tried to align and torque them.
Taped off or removed the front splitter because while standing in front of the car to work, the splitter effectively pushes you away from the car causing you to have to lean further. Very taxing on the hamstrings and low back.
Took more pictures of places that are hard to reach. The last thing you want is to forget how the rear of each head was configured with all the wiring loom brackets and grounds. In fact, I wish I would’ve done a video walk around of the engine bay from different angles.
Drained more coolant. I’m not sure if the z/28 holds more than expected? But when I cracked the seal on that first head it was a mess.



My initial thoughts on driving impressions/performance/any differences compared to stock:
The first initial cold start was oddly quiet and not as violent. Didn’t have the same loud clearing it’s throat exhaust explosion, but since then it does it as you’d expect. The normal lifter sewing machine noise is definitely a lot quieter. Which is expected with such a quality valve job and the tolerances AHP adheres to for runout and concentricity. As far as seat of the pants power increase? I didn’t have any porting done. But they claim a small bump with just the valve job. So power increase for me is negligible although it does seem to rev smoother. This may have something to do with the small increase in weight of the hollow SS valves compared to the lighter factory two piece. My rockers are now upgraded as well to the C.H.E. Trunnions and they absolutely go through their range of motion smoother than the stockers. You’ll see for yourself if you ever assemble them. My kooks headers were damn near impossible to get aligned and clamped down to avoid any leaks. It uses the cheap wanna be v band style clamp to compress the collector over the inlet of the CATS. The very next day I was at an S&S exhaust shop to have flanges welded on to get rid of the leaks and make for an easier disassembly/re-assembly in the future if needed. (Like 120.00, money well spent IMO).



Car runs great now. Love it. Great feeling of accomplishment and it’s good to have piece of mind knowing the heads are in order. I will update this later on info about my factory heads and if they were out of tolerance and if so how far.

Thinking about doing this initially seemed impossible. But after doing it I see it wasn’t that hard! Save yourself some money or if you’re nowhere near a good shop, do it yourself. It’s kind of fun too!

[johna]

Wow
Amazing post!
Thanks


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[MX621]

Excellent post, should be a sticky!! ����. By any chance is AHP gonna report the valve guide wear on your old heads?

[BJJKRIS]

Originally Posted by MX621

Excellent post, should be a sticky!! ����. By any chance is AHP gonna report the valve guide wear on your old heads?

I’ve heard you have to ask for that info. Which I will when I send mine back in. I’m hoping they’re all messed up so I feel better about all this work haha


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[MX621]

Originally Posted by BJJKRIS

I’ve heard you have to ask for that info. Which I will when I send mine back in. I’m hoping they’re all messed up so I feel better about all this work haha


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Haha I hear ya. How many miles on your car ( sorry if you already posted that). I plan to take similar action on my car over the winter when my warranty is up. Fantastic how to! Thanks for taking the time!

[BJJKRIS]

Originally Posted by MX621

Haha I hear ya. How many miles on your car ( sorry if you already posted that). I plan to take similar action on my car over the winter when my warranty is up. Fantastic how to! Thanks for taking the time!

Just hit 20,000. And yep. All our warranties are up soon!


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[pzero]

Great post. Thank you for your time and detail information. Love reading DIY projects on a Z/28. Not much information on Z's period. Thanks again and thank you for your service in the military.

Would be nice if they had a sticky for all large or small DYI projects on a Z/28.

Me...US Army Vet.

[BJJKRIS]

Originally Posted by pzero

Great post. Thank you for your time and detail information. Love reading DIY projects on a Z/28. Not much information on Z's period. Thanks again and thank you for your service in the military.

Would be nice if they had a sticky for all large or small DYI projects on a Z/28.

Me...US Army Vet.

Thanks man! And thank you for your service as well! The fact that theres not a lot of info on our cars is why I put this together. You can absolutely get by with the DIY info for a ZO6 or really anything with any LS variant but I know there’s a lot of people like myself that feel better with having detailed instructions and no guess work. Plus any info is good info in my book.


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[ImDaBaron]

Thanks for posting this man. Been wanting to do this head swap for a while. Just have to wait for my other projects to get done so the Z28 can be down for a while. But it's getting a cam upgrade here really soon so I've been using the Z06 guides. But this has been extremely helpful.

[BJJKRIS]

Originally Posted by ImDaBaron

Thanks for posting this man. Been wanting to do this head swap for a while. Just have to wait for my other projects to get done so the Z28 can be down for a while. But it's getting a cam upgrade here really soon so I've been using the Z06 guides. But this has been extremely helpful.

No problem man I’m glad you find it useful! I’m not 100% positive but I think removing the fans and radiator as one unit is in order for a cam install.


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[ImDaBaron]

Originally Posted by BJJKRIS

No problem man I’m glad you find it useful! I’m not 100% positive but I think removing the fans and radiator as one unit is in order for a cam install.


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How long did it take for you to get the heads from them?

[BJJKRIS]

Originally Posted by ImDaBaron

How long did it take for you to get the heads from them?

About 10 days. I started pulling mine off when I got the shipping confirmation.


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[Sakudog]

I am Jeffreystar aka Sakudog, glad to have helped the Z/28 family!

[BJJKRIS]

Originally Posted by Sakudog

I am Jeffreystar aka Sakudog, glad to have helped the Z/28 family!

The legend has spoken! Thanks for doing the hard work first!


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