Exhaust Manifolds

One of my buds in the 70's bought a 70' Duster 318, bone stock internals w/3spd and 3.23's. With a LD4b, 600 Holley, regulation headers and 2.5 exhaust installed went 15.00 at 91mph on multiple occasions. That's about 200 net hp. I doubt a 72/74, non hp, 340/360 style manifold would have slowed it down much.

The reason i bring this up is, would you be happy with that level of performance?

If no and you'd want to build on that later, then save the coin and buy the the good coated headers up front. You'll be glad you did later.