Rx catch can install question on L99 to LS3 conversion

[Agent WD-40]

I have a L99 with an LS3 conversion. I'm trying to make sense of exactly which lines I need to connect my catch can to. I've posted a few pictures. Any help would be welcome.

As you can see from the 2nd picture I have a cover over the vent where the normal line for the L99 connects. The 3rd picture shows how the breather line in from the air intake connects to a line coming out of the valve cover.

[IndeedSS1]

On an LS3 you just remove the small horseshoe hard line right behind the throttle body and the hoses from the catch can connect there.

In your last picture you can see the back end of the horseshoe very close to your line from the air intake.

[Agent WD-40]

Originally Posted by IndeedSS1

On an LS3 you just remove the small horseshoe hard line right behind the throttle body and the hoses from the catch can connect there.

In your last picture you can see the back end of the horseshoe very close to your line from the air intake.

Unless I'm missing it I don't see the small horseshoe piece. I guess the whole LS3 conversion is not 100% accurate. I really have more of a DOD delete kit. I'm not sure exactly what parts are used with this. It doesn't look exactly like the LS3 as far as I can tell so I am sort of stumped.

[IndeedSS1]

Originally Posted by Agent WD-40

Unless I'm missing it I don't see the small horseshoe piece. I guess the whole LS3 conversion is not 100% accurate. I really have more of a DOD delete kit. I'm not sure exactly what parts are used with this. It doesn't look exactly like the LS3 as far as I can tell so I am sort of stumped.

Unless the valley cover was changed, wouldn't you hook it up to the same place as your original L99? Where does that piece connected to the intake snout go behind the throttle body on the passenger side? In the picture all I can see is the bend of the hose.

[Agent WD-40]

Originally Posted by IndeedSS1

Unless the valley cover was changed, wouldn't you hook it up to the same place as your original L99? Where does that piece connected to the intake snout go behind the throttle body on the passenger side? In the picture all I can see is the bend of the hose.

The valley cover was changed to an LS2 cover.

I have the Livernois Motorsports conversion on mine. According to their web page they used a GMPP LS2 valley cover, GMPP Valve Cover Breather block off (which I think is the thing in the 2nd picture blocking the place the standard L99 connection spot), and the GMPP PCV Hose for Non-DOD applications.

[Agent WD-40]

Originally Posted by IndeedSS1

Unless the valley cover was changed, wouldn't you hook it up to the same place as your original L99? Where does that piece connected to the intake snout go behind the throttle body on the passenger side? In the picture all I can see is the bend of the hose.

Ahh, I see what your talking about. Sorry, I clearly don't fully understand what I'm trying to do here. I was just trying to match picture A to picture B and couldn't.

So, that hose comes out of the valley cover and is plugged in somewhere behind the TB. I cannot really get a good look down there. The spot that the stock L99 tube ran to (rear of the drivers side valve cover) is blocked off as far as I can tell.

I put a few more pictures up to make sure this is the correct thing.

So one more bonehead question to make sure I really get it. If that small section of hose shown in my new pictures is indeed where I need to connect my catch can, the center fitting connects to the valley cover and the outside fitting connects to the nipple on the intake just behind the throttle body?

[IndeedSS1]

Awesome. It connects just like the LS3. Remove the short piece of hose connecting the valley cover to the intake manifold. Connect one hose from the valley cover to the center fitting on the RX catch can. And of course the other hose between the intake manifold and the other most catch can fitting.

Oh and yes on the L99 a length of hard line ran from that capped off line to the intake manifold. Now that the valley cover is like the LS3, the capped off line stays capped off and simply taking off that short hose and installiin the catch can is all that's needed. But I think you had already figured it out.

[SC2150]

Thats correct! Thanks guys!

[Agent WD-40]

Just got it installed! Thanks for the help!

Where is everybody routing the drain hose though?

[SC2150]

I run it down along the radiator shroud and trim it so it hangs down just enough to slip a drain pan under it for easy mess free draining.

[IndeedSS1]

I have a 1/4 ball valve with no hose on mine. I open the valve while holding a vienna weinnie can underneath. Open, close, done. 5 seconds max.

[Agent WD-40]

I'm going to stick with my drain tube routing down the side of the fan shroud for now. I have the end zip tied to one of the AC compressor or power steering lines down there. I might trim it and just hold a water bottle under the can as it drains. I guess I'll see.

Here is the finished product! Thanks again for the help.

[IndeedSS1]

Looks good and I'm sure your thread and pictures will be of help to others.

[cm5217]

Ok so it seems mine is wrong I had the can before the conversion and it seems they left it hooked up as it was In the first pic you can see the red cap on where the can should be hooked up and in the second pic you can see they left the rear drivers side hooked up like it was L99. Do i need to change this or will this still work?