Ive always fancied dropping in a 5.7l hemi and getting 345hp stock but I would get a donor truck that someone wrecked and steal the tranny, computer, etc. But the 318 crate motor sounds like a good deal I would do that as it will go into your truck easier. But on the Hemi note a trip to the auction wouldnt hurt see what you can find.
"Courage is the resistance to fear, the mastery of fear, not the lack of fear." Mark Twain