manifolds VS headers, amto of gain?

I waited to see how the car performed.
Mosta the lower lap times came from chassis adjustment, and driver improvement.
I never did put a header on it, cuz the powers that be wanted us to add weight, so I just threatened to put on legal headers, that everyone else was running, - that shut them up.

Headers generally gained 2/10ths/lap to most cars.

They Do make a difference .