Hey guys I am putting in an LT1 in an 89 Camaro. I know I can use 3rd gen headers. But what size? I am sure that the 1 3/4 are better but can I still use 1 5/8? I have a lead on some I can pick up cheap.

 

You can get away with the 1 5/8" headers but you may have to grind on the inside lip a bit if it interferes with the D-port. Some 1 5/8" headers are a bit smaller than they claim because of the weld. It may need a little massaging to get it right. I recently read an article on this and they said the lip didn't restrict any power. The grinded on the header a bit and smoothed it out but didn't see any power gains.

 

I just pulled my exhaust manifolds on my LT1 yesterday and I have some SLP 1 5/8" headers (for a thirdgen) and they lined up perfect. BTW, congrats on becoming a moderator shifty.

 

Hey thanks. Was there any overlap of the header weld by the head port?

 

Nope, fitment was perfect.