who makes a big header to fit in a f-body car?

 

1-7/8 is the biggest regular production header I know of (you might be able to get something bigger if you have them custom made). I would go with Kook's if you are looking for the best by consensus. There are a bunch of other ones out there too. I would stay away from QTP, I had a set and they leaked like crazy. Edelbrock recently started making them too, but I think the collector is slip on (and may leak), but they are cheaper.

-Geoff

 

Kooks makes a 2" primary with 3.5" collector and a 1 7/8 stepped to 2" primary with a 3.5" collector

IIRC the non-stepped 2" primary part requires a tubular k member.

edit: I believe ARH or stainless headers also makes a 2" primary header

 

tsp has a pretty nice set

 

ARH or KOOKS. I'm not aware of any NON-Stainless Steel headers in the large sizes.