Missed on this combo?

I'm interested to see what you figure out. Your torque seems way low, especially in the low-mid range. I think you should try a better carb, good 1" spacer, and some 3" collectors with 18" extensions on them before messing with the cam. Not that the cam is not part of the problem, but I think doing those other "fixes" would get you close to your goal and improve the torque.
FWIW, I also have Hughes ported Iron Ram heads on my stroker, but with 2.055 inake valves, and the numbers were right on what Hughes advertised when Brian at IMM checked them.