Don't show more of a HP gain,considering how restrictive looking the factory log manifolds are. I mean they look like something from the 50's!!! For instance,and I know this is apples to oranges,a test on a new 1971 340 Dodge Demon,rated at a real 275 HP,picked up a half second in ET,and gained 4 MPH in the 1/4 mile with a cheap set of street headers,through the stock mufflers,no other changes. These cars came with good flowing cast iron exhaust manifolds. Opened up the Demon ran 13.6s at 104 MPH vs.14.4 at 98.6 with stock manifolds. Not bad for an $ 80.00 mod! You would just think that the Bullitt would pick up more than 3-5 HP with a shorty header,considering the shape of the stockers.
<font size=-1>[ This Message was edited by: Mus408 on 2002-01-14 19:55 ]</font>
<font size=-1>[ This Message was edited by: Mus408 on 2002-01-14 19:55 ]</font>