That's a tough one, The quickest sale item you have are the Apache heads, that crank is an odd piece, but it's something that I would buy....but I can be an odd guy.
Established G3 builders have an easier time selling complete runners than "hobbiest" I have no doubt that a G3 that you would build, will be a good solid beast, but the crowd who are deep into these hemis seem to be clickish, I think some of it is because so few people really know how to squeeze that extra HP out of them.
My opinion on selling parts right now is, unless your willing to take a hit, it's hard to sell, not sure if it's economics or too many keyboard racers.
I don't envy your decision.