427 block with GPI Max Performance heads? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

PumpinIron · 07-10-2019, 07:38 PM

I recently ordered the GPI Max Performance package and MSD intake manifold.

In the near future I plan to do the bottom end. I'm well aware I can do a 416 block and keep the heads, but I'm curious as to whether I can do a 427 and retain my GPI Max Performance heads, or if that would require a different block and heads?

You'll have to forgive me since I'm new to Camaros (coming from BMW M cars) and LS engines in general.

Thanks!

KW Baraka · 07-10-2019, 11:35 PM

If you're talking about a stroked, 427ci LS3 or a LS7 engine (also 427ci) with ported GPI LS3 heads......no problem; they'll match.

On the other hand, the MSD intake will be for LS7 heads....LS3 heads will not work with that intake.

KW

PumpinIron · 07-11-2019, 12:03 AM

Quote:

Originally Posted by KW Baraka

If you're talking about a stroked, 427ci LS3 or a LS7 engine (also 427ci) with ported GPI LS3 heads......no problem; they'll match.

On the other hand, the MSD intake will be for LS7 heads....LS3 heads will not work with that intake.

KW

Yes, I have the GPI Max Performance heads (modified LS7 heads as I understand it) on my LS3. I'm wanting to stroke the LS3 block and turn it into a 427ci. I just wasn't sure if that could be done to my existing LS3 block or not, since most of the guys seem to be running 416, and I wasn't sure why that is.

weSS1LEy · 07-11-2019, 02:28 AM

So the bore of an ls7 is different than an ls3 so I don’t understand how these heads could match both. Unless you have ls7 style heads that match the bore of an ls3 then you would stroke the ls3 to 427 but leave the bore as ls3. So you would end up with 427 but not ls7. Someone educate me on this please.

frankwjr · 07-11-2019, 10:36 AM

If you have already spent $$$ with GPI, why would you not ask them? I believe the GPI max head is for the LS3, LS7 block entirely different animal and different head pattern so not compatible.

Peeps run a 416 vs 427 stroke due to reduced piston rock a BDC.

good luck!

PEACE

zz430camaro · 07-11-2019, 10:51 AM

Ls3 heads should fit a 427

Roader · 07-11-2019, 11:57 AM

The other thing to look at is the aero force is a good IM but you’ll want to go to something different for a Mac effort 427 build. I saw a post, maybe an article, that it actually restricted compared to a high ram. Other than that I don’t know much about the aero force other than the 6th gen guys are getting really good results from it on sbe

PumpinIron · 07-11-2019, 11:44 PM

Quote:

Originally Posted by Roader

The other thing to look at is the aero force is a good IM but you’ll want to go to something different for a Mac effort 427 build. I saw a post, maybe an article, that it actually restricted compared to a high ram. Other than that I don’t know much about the aero force other than the 6th gen guys are getting really good results from it on sbe

The AirForce Atomic manifold is supposed to make pretty good power, but I guess we'll see. I won't know for sure since I'm installing the complete GPI package all at once, including the intake manifold.

As for a high ram, does that require a bigger hood?

WHAMMO · 07-12-2019, 12:27 AM

Quote:

Originally Posted by PumpinIron

The AirForce Atomic manifold is supposed to make pretty good power, but I guess we'll see. I won't know for sure since I'm installing the complete GPI package all at once, including the intake manifold.

As for a high ram, does that require a bigger hood?

Hi ram needs cowl/ hood cutting. LOD is the intake you want to clear everything get the most of it.

PumpinIron · 07-12-2019, 01:23 AM

Quote:

Originally Posted by WHAMMO

Hi ram needs cowl/ hood cutting. LOD is the intake you want to clear everything get the most of it.

Why is it that I can't find a price anywhere on the internet (or at least in my Google searches) for that LOD X1 manifold?

Roader · 07-12-2019, 06:21 AM

Quote:

Originally Posted by WHAMMO

Hi ram needs cowl/ hood cutting. LOD is the intake you want to clear everything get the most of it.

I’m not advocating for one over the other. just what was used on the application in the article. Just to be clear before a few people jump in here with their opinions

Clarkstar · 07-12-2019, 07:00 AM

Quote:

Originally Posted by PumpinIron

Why is it that I can't find a price anywhere on the internet (or at least in my Google searches) for that LOD X1 manifold?

Www.lodspeedworks.com

lazerlemonta · 07-12-2019, 07:48 AM

The LS7 version is just around the corner. He will not find it yet........ Title of this thread is very misleading as well. You have an LS3 block and would be stroking it to 427 instead of 416. If you decided to purchase a LS7 block and build it you could then turn it 7800-8000. A stroker LS3 427 most are going to say 7200 to be safe.

l.o.d_yankee · 07-12-2019, 08:55 AM

Quote:

Originally Posted by PumpinIron

Why is it that I can't find a price anywhere on the internet (or at least in my Google searches) for that LOD X1 manifold?

$1450+shipping and tax. The website is being revamped right now. I found it hard to find the price myself.

07-10-2019, 07:38 PM	#1
PumpinIron Drives: 2013 Camaro 2SS Join Date: Jun 2019 Location: Salem, OR Posts: 115	427 block with GPI Max Performance heads? I recently ordered the GPI Max Performance package and MSD intake manifold. In the near future I plan to do the bottom end. I'm well aware I can do a 416 block and keep the heads, but I'm curious as to whether I can do a 427 and retain my GPI Max Performance heads, or if that would require a different block and heads? You'll have to forgive me since I'm new to Camaros (coming from BMW M cars) and LS engines in general. Thanks!

07-10-2019, 11:35 PM	#2
KW Baraka Drives: 2014 Chevy SS Join Date: Nov 2014 Location: San Antonio, TX Posts: 277	If you're talking about a stroked, 427ci LS3 or a LS7 engine (also 427ci) with ported GPI LS3 heads......no problem; they'll match. On the other hand, the MSD intake will be for LS7 heads....LS3 heads will not work with that intake. KW __________________ 1995 Impala SS -- Heads/Cam LS3 1996 Impala SS -- 398ci LL Solid Roller LT4 2014 Chevy SS --- 429ci Hydraulic Roller LS3

07-11-2019, 02:28 AM	#4
weSS1LEy weSS1LEy Drives: 2015 camaro 2ss/rs/1le Join Date: Sep 2015 Location: Kelowna Posts: 510	So the bore of an ls7 is different than an ls3 so I don’t understand how these heads could match both. Unless you have ls7 style heads that match the bore of an ls3 then you would stroke the ls3 to 427 but leave the bore as ls3. So you would end up with 427 but not ls7. Someone educate me on this please. __________________ Rotofab, arh no cats, atak, elite cc, 94 octane tune, Mobil 1, phastek scoop, custom cam 230/243 .621 .604 114+4, related cam kit stuff. 470/435 rwhp/rwtq

07-11-2019, 10:36 AM	#5
frankwjr Drives: 2010 SS 2SS M6 Join Date: Aug 2016 Location: Smithsburg, Md. Posts: 2,445	If you have already spent $$$ with GPI, why would you not ask them? I believe the GPI max head is for the LS3, LS7 block entirely different animal and different head pattern so not compatible. Peeps run a 416 vs 427 stroke due to reduced piston rock a BDC. good luck! PEACE __________________ 2010 SS 2SS M6 - Tune by RDP dynoSteve!(Woot) - Daily Driver - *150K!* - All work by me...

07-11-2019, 10:51 AM	#6
zz430camaro Drives: 2015 1LE Join Date: Oct 2015 Location: Cleveland, OH Posts: 1,498	Ls3 heads should fit a 427 __________________ 2015 1LE, TSP 225/236 113+3, VMAX Throttle Body, CAI with race scoop, GPI Ported Intake, Land Speed Stage 2 Heads, 1-7/8 headers, NPP exhaust, 25% Fluidampr, LT1-S Monster Clutch, 485 RWHP & 444 TQ

07-11-2019, 11:57 AM	#7
Roader Drives: Camaro Join Date: Oct 2018 Location: Alabama Posts: 673	The other thing to look at is the aero force is a good IM but you’ll want to go to something different for a Mac effort 427 build. I saw a post, maybe an article, that it actually restricted compared to a high ram. Other than that I don’t know much about the aero force other than the 6th gen guys are getting really good results from it on sbe

07-12-2019, 07:48 AM	#13
lazerlemonta Drives: 2010 C6 1LT Join Date: Dec 2011 Location: Virginia Posts: 887 View My Garage	The LS7 version is just around the corner. He will not find it yet........ Title of this thread is very misleading as well. You have an LS3 block and would be stroking it to 427 instead of 416. If you decided to purchase a LS7 block and build it you could then turn it 7800-8000. A stroker LS3 427 most are going to say 7200 to be safe. __________________ 2010 C6 JET STREAM BLUE BOLT ONS TO THE EXTREME, GPI 281cc HEADS, Darth_V8r SPEC CAM, FAST 102 INTAKE, CRANK SCRAPER, QUARTER MASTER 7.25" CLUTCH, RPM 3.90 STAGE II DIF, Z51 Gear Set AND E85 Best ET 10.58 @ 131.8 stock heads and stock cam 453/445 SAE 10.62@134.82 GPI 281CC Heads, SS4 Cam and X1 Intake Best 1/8 6.80@105.75 Best MPH 134.82