I'm in the market for new headers/Y-pipe for my '83 Trans Am with an LG4 and 5-speed. My current exhaust setup consists of stock manifolds, Y-pipe and cat, then 3" intermediate pipe to an Edelbrock SDT muffler (2.5" ID and OD).

Now, my #1 pick would be the Hooker 2055 headers with 3" Y-pipe because then I can get a 3" Catco cat and have 3" all the way till the muffler. One thing that I'm confused with is that I'm not sure why it says the application years are '86-92...why not earlier?

There are others in consideration (Hooker 2460, Hedman 68471, Edelbrock 68563), but they all either come with or have an optional 2.5" Y-pipe and I'd either have to get a 3" cat with an adapter for the Y-pipe, or a 2.5" cat with an adapter for the 3" intermediate piping.

The headers I've compared also all have the A.I.R. and I'm not sure if I absolutely NEED it...but since the car has it factory, I think it'd be a good idea to keep it. Also, I read from five7kid that the Hooker 2460

I guess I'm not an exhaust expert, so I'm asking here for people who do know.

Also, is the 2.5" ID sized muffler a bad idea as well? I just got the Edelbrock SDT muffler because it was on sale for a really good price.

 

Because you can't unbolt the stock system forward of the cat and bolt those headers in for any applications other than '86-'90 TPI single cat (not '86-'92 as you stated).

It won't be a problem, other than needing to modify the cat-back inlet for the Catco direct-fit (minor problem to have).

The 2.5" core muffler won't be a problem for a stock LG4.

 

I was wondering if there is any problem hooking the A.I.R. (what does that stand for) up using the hooker 2055 on a lg4