Slant six dual exhaust vs. 2-1?

What car and year? What engine and what have you done to it?
It’s a 74 Dart Sport with a 77 225. I haven’t done anything yet but I’m accumulating parts to hot rod it. I got a cam already (.440 lift on both intake and exhaust, 264° duration) I ordered a redline intake manifold to do triple Weber 45DCOE setup and I plan to run Dutra Dual headers.