I have a stock '89 305 powered car that is going to get some mods this summer as time and my meager budget allow. A little research seems to indicate that the stock exhaust system on our third gen cars is probably the single worst performance bottleneck that we have to deal with. There's a guy in town who is parting out a third gen that has an LT1 and T56 transplanted into it. He's running headers and has an aftermarket y pipe. Will the LT1 headers bolt onto my heads, and should there be any clearance issues for me if they work on his car? I'm wondering about whether the LT1 has raised exhaust ports over the gen 1 and whether this will cause clearance issues. The exhaust bolt pattern is the same, isn't it? I'm thinking that I could bolt his entire exhaust system to my car.

Thanks in advance for your thoughts!

 

the LT1 has basically the same bolt pattern and gasket pattern, they should fit fine. For that matter, most likely if it was in a 3rd gen, they were probably just 3rd gen, SBC headers.

 

Thats exactly what they are. They dont make LT1 3rd gen swap headers, they just make different types of 3rd gen headers, some even with 'D' port primaries.

They will bolt up and work perfectly fine.

 

I said probably because I know for a fact that some 4th gen LT1 shortie headers _will_ fit in a third gen, but I have used 3rd gen SBC headers on an LT1 swapped into a 3rd gen. Most headers have taller ports than normal exaust ports or round ones that work fine with the D-ports on an LT1, but some may cover them slightly which can be fixed in a few minutes with a grinder.

 

actually, even better, just remembered that you're putting them back on the SBC... at worst you'll have a slightly bigger opening at the top of the port which will work as an anti-reversion step (a good thing).