I thought about going that route but instead I'm going to have one built at the local machine shop. It'll be basically the same motor with a few tweaks for a little more rev.
I also have this, its my brother and I's project. 73 k5 blazer custom cab. It has a motor home 454 bored 30 over, eldelbrock rpm manifold, edelbrock 650 carb, and Doug thorely tri y headers. She's got a 4 inch lift and 35x 16 inch wide boggers and a posi front and Lincoln locker rear. At 5mpg and current gas prices not the most practical hunting rig.