HumpinSS

iTrader: (1)

How come all of the companys only sell 1 3/4 headers for the LS1. I never see any 1 5/8" headers for Ls1 F-bodies. To my understanding 1 3/4 were used more for race applications rather than street setups and since the LS1 isnt actually 350 ci it really should be using a smaller tube header such as 1 5/8".

Can someone give me a little insight on this

Red02LS1

Because the exhaust side of the ls1's flow so well, when you go to the 1 5/8" you will loose power.

HumpinSS

iTrader: (1)

Bump

TA_2001

exhaust theory
http://www.ls1info.com/article.php?sid=166

Colonel

The more power you're making (in other words, the more air you're flowing) the more important larger diameter primaries become.

I'm running 1 7/8" headers.