The subject says it all. What are the possible configurations that would not require major fab work? I'm not just talking cat-back, I'm talking from the manifold all the way back.

As it says in the sig, I have a 90 LO3 with 2 1/4" exhaust (or whatever was stock). I'm looking to beef that up to 3".

One more thing...I've read that there are 3rd gen headers that will bolt on to an LT1. How true is this, and is it applicable to the exhaust setup that you recommend?

Thanks.

 

Go for Heddem headers to a 3" Y-pipe to a highflow cat 3" with a Hooker Cat-Back.

 

All thirdgen headers will bolt to an LT1, because the exhaust bolt pattern on the heads is the same. You want to get thirdgen headers and not 4th gen headers, becuase they are made to fit the car, not the engine. My recommendations for that would be SLP 1 3/4" headers. Get in on the group purchase in the thread at the top of this forum.

For exhaust, pretty much all the manufacturers make cat-backs for our cars. Pick whichever one you like. And they almost always require some modification, especially since you'll be bolting it to headers and a high-flow cat.

 

I have slp 1 3/4 headers on my car(with the lt1) I like them very much. The headers are actually big enough to not couse a major restriction in the exhaust port. You will need to have an extra 02 bung welded into the passenger side header. You will also need to have a fitting for the air tubr welded onto the pass side header also.
Hope this helps.
Kory

 

Correct me if I'm wrong, but aren't many of the thirdgen headers available with provisions for the AIR?

 

I have the SLP 1 3/4" Shorties w/o Air. They fit the engine really well. I did run into a problem of the y-pipe rubbing the floorboard near the front right ground effect, behind the front right tire (The place where the two header pipes turn into one 3" tube). Anyways, we had to just bend the y-pipe down a little.. no biggie. FYI: I'm also running a flanged 3" straight-pipe and 3" Flowmaster American Thunder 3" IN/OUT Muffler. This setup is a little quiet at idle, but is just outright NASTY when you get on it. Seriously, I've had mustang owners compliment the sound of my IROC. My LT1 is comletely stock too. Actually, when I start modding my engine, Im going to be upgrading exhausts-- Hooker LT's, 3" Y-pipe (No Cats), and 3.5" Catback w/ single chamber 3.5" Single IN/OUT Flowmaster muffler. I can't wait! bwhahahaha

 

Uhm... Why do you need a second O2 sensor? And why do you need another fitting for the AIR tube?

 

Kevin91Z: LT1's have two oxygen sensors. The SLP headers only come with 1 O2 provision, so you have to weld in an O2 bung on the other side. I don't know about the A.I.R., though because my headers don't have A.I.R.

 

I'm using Hooker Super Comp Long Tubes with my LT1.

 

:hail: LONG TUBES! I really want a pair of those. How do those long tubes make your car sound? Have you noticed any performance benefits from them? Thanks

 

I haven't finished up with the swap yet (the DFI still needs to be installed). But on fourth gens Long tubes give an extra 10-15 HP over shorty style headers, and the difference between shortieas and LTs grows bigger with bigger mods. Listen for some Long tube sounds on CZ28.com and you'll hear the difference. It is pretty mean!

 

I appreciate all of the replies, but I'm bumping this ttt to try to get as much input as I can from other LT1 swappers.

 

My friend Brett doesn't post here really any longer, but he also put an LT1 into his RS. He's using an SLP setup and he really seems to like it. Remember, any thirdgen exhaust setup will bolt to that LT1, so you have really unlimited options.

 

Oh yah, duh! Ooops.

 

I'd really prefer to use thirdgen headers, but since I'm still a few months away from this swap, I'm kicking around all possibilities. What about the stock LT1 exhaust manifolds. I've heard that Vette manifolds are no good because they dump to the middle of the car, but I haven't heard about the stock F-body manifolds. Anyone?

 

The stock manifolds will work, but you have to cut and weld the y pipe.
Kory