Are the exhaust ports on the '96 LT1 a "D" port head? I see various headers for angle plugs and "D" port heads. And other headers for just Angle plugs.
Some of the headers come with 1-1/2" pipes and others with 1-5/8" pipes. Which size doe the '96 LT1 require? THANKS

 

LT1 heads have D-shaped ports, but will bolt up to any SBC header.

I can only assume you're putting this engine in something other than an f-body, because f-bodies require f-body specific headers. Most aftermarket headers for f-bodies have 1 5/8" to 1 7/8" primaries.

 

D-port as the guy above me said (just backing him up)