Yeah but don't forget how much dough the FAST guys are dropping into having stock manifolds ported, or exrude honed or whatever they call it. The 6 pack intake is a good one for making HP, and you can put down some nice #'s with stock HP manifolds. With a stock 4bbl intake, not so much. Can still make some power, but it is way more restrictive than a 6-pack intake, which flow and performance wise keeps up with the modern street/strip intakes. With the right cam selection you can do a lot with the stock HP manifolds, but you would still gain more if changing to headers.

My engine builder said that extrude honing the exhaust manifolds would probably not have any effect on my engines performance/speed/time. It may be something that the top F.A.S.T. guys are doing looking for any millisecond advantage, but certainly not worht the money that it cost for anyone else.

What is it that you think looks cool, it is all inside of the manifolds?