318 build #2 "cost minded" for the '74 Duster

DionR said
Just saying that pointing to that test and saying the HP manifolds or headers are worth only ___ hp is flawed. Put something better than the broomstick cam it came with in and make the exhaust the restriction and (I think) the differences will be greater. Which means the magazine test is useless when applied to something other than a 300hp crate motor beyond the generalizations that tube is better than cast iron.

have seen test on 340s with a cam etc they lose 15 20 hp over headers up top
clearly they will loose more as power goes up
60 to 80 on a stroker dyno i watched
all i said is id like to see the difference on that motor with a twin stage shot of spray
might matter less with a mild build if so its another way for a lower cost motor to get good power