[LT7A]

If you want to see some real world testing of different setups, search Gregski's build of Rusty. It's good entertainment and will give you some background. I have no personal experience with headers and have no reason to doubt any of the advice previously given above. I plan installing a set in the near term, so I jumped on this thread to check out the advice. I just remember Gregski doing a lot of experimenting -- he may have actually gone back to exhaust manifolds. In which case I apologize for pointing you in a direction that doesn't offer a solution.