Treblig's doughnut?

Not everybody wants or needs headers, especially on a mild, street-driven build. 340 manifolds, especially, hardly constitute "castrating" an engine. If they were teener or 273 manifolds you could make a case for it, but the 340 and Magnum mannys are different animals. Might even gain some bottom end over the headers, depending on your build. And you lose all the inherent problems of headers on daily drivers, as stated. Look at F.A.S.T. cars- up on the back tires with stock-type exhaust and DOT bias-plies...