Is there a difference between L03 exhaust manifolds that come on '88-'92 F-bodies and L03 manifolds that come on '89-'92 Caprices besides different y-pipes, i.e. could you use a manifold from a Caprice on an F-body? And are the L05 manifolds from Caprice/Fleetwood/Roadmaster the same as TPI or L03 manifolds?

 

should be the same basic thing. same mounting at least, although the angle of the outlet may be different depending on the application. like on my truck the manifold outlet is near straight down, whereas on the f-body i believe it is angled back more. experiment and good luck

 

What about LU5 crossfire manifolds? Is there any difference between the LU5 and the LO3 manifolds? I'm asking because I'm restoring my Iroc to as close to original as possible, it will be a cruiser mostly. I currently have Edelbrock TES headers and a Flowmaster(American Thunder) cat-back on the car now. I want to put factory manifolds and y-pipe back on it and a quieter 50 series 3 chamber muffler. TPI y and intermediate pipes are a little costly new' that's why I'm asking about LO3 and LU5 exhaust manifolds, both of which I may have easy access to.

 

As far as I know, the only manifolds and y-pipe that will work with thirdgen f-bodies is other thirdgen f-body parts. The angles and direction of the pipes are specific to our cars.

And the L03/LG4 stuff is smaller and made for low-power. Keep trying to find the good TPI stuff.