header size
 

Are 2 1/8 " headers to big for a 396 in stock?

Re: header size
 

Probably. Especially if it has the 401 aluminum heads. The best 4 into 1 header would be a 1-7/8" to 2" to 2 1/8" Stahl. About 30" to 32" long, with a 3" to 4" merge collector about 15-1/2" long. A 2-1/8" header would work for a 427, but probably not for a 396. It would probably hurt torque too much for a 396, especially if it was in front of an automatic.

Re: header size
 

way too big!