If you want something that will still look like the original engine and give you lots of reliable Hp, find a 270/302 GMC. They were designed before the companies decided to save every penny by making things as weak as they could get away with. and they along with other inlines cost less to build--especially if you can run a torch and die grinder to do the head and make your manifolds!
Holiday cheer;
ROAR :p
