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Third gen Firebird LS swap with LS3 exhaust manifolds
Has anyone used them successfully?
I'm in the process of swapping a 4.8/ 4L60E into an '89 'bird. It's just going to be a stock swap to get rid of the pathetic, leaking 2.8 that it came with from the factory.
I've been doing a lot of research about this over the past year or so, and decided to use LS3 exhaust manifolds because I heard that they were a sure fit.
Also, I didn't want to take my chances with 20 year old LS1 manifolds that might crack.
So I bought a set of LS3s off of Ebay about 6 months ago, and I finally got a chance to mock them up on the engine.
Yes, technically they fit, but the passenger side is dumping right on the lower control arm mount, and the driver's side is much closer to the floorpan than I'd like.
Passenger side, seen from the top. Passenger side outlet, seen from the top. Passenger side, seen from the bottom.
Driver's side outlet.
Can anyone offer any advice on this?
For the record, I'm using UMI frame perches with factory style F-Body mounts, and a modified factory trans crossmember.
I don’t think those LS3 manifold will work, I’d look for CTSV manifolds / 2000+ LS1 manifolds or C6 LS2 manifolds. They all have short outlets and have a flatter angle vs those gen 5 camaro manifolds you currently have. Check out the link below to see how they look! Good luck
01-21-2019 | 07:05 PM
Third gen Firebird LS swap with LS3 exhaust manifolds 
