i'd always steer toward alum aftermarket heads if the price was the same or close.
but! brand new heads still need to be checked out, they're rarely ready to run OOTB... which means a trip to the machine shop and mas dinero. and then tack on some more coin if you need to update springs/locks/keepers blah blah blah.
now if the ported iron heads are rock and roll ready to snap on and run: hardened seats, the springs match the cam you want to run, good valves that are cut proper, good guides, fresh seals, and so on and so forth... that may sway my decision.
if the speedos are some take offs that were already run and somebody already did all that, and they weren't rode hard and put away wet then that's the play there.
