Hello, long story short i have a free set of shorty headers (no brand indicators) that came from a 1991 firebird with a 400 sbc. I'm trying to figure out if these will fit in my 1991 camaro 305tbi or do i have to buy new ones? They measure out being 3 out (2 3/4in inside to inside) and almost 1 5/8 in. If anyone could share some input it would be greatly appreciated. Also, if these do work, are they any good and recommendations for a y pipe would be awesome. Thanks Guys! Trying to save money and gain hp over the stock manifolds.

 

Those are flowtech headers. Check summit racing or jegs to see the compatibility list. Although, you'd need to know what the heads were for the 400 sbc to see if the headers will line up if it isn't a stock motor. They look like standard sbc headers, though, but you can also check the dimensions online to be sure.

 

http://www.summitracing.com/parts/bi...et?prefilter=1