+1 for the Cadillac 500. It's actually about the same weight as a small block Chevy, and it develops a ton of torque. I put over 300,000 miles on a 472, which is a virtual clone of the 500, just a bit older and smaller. Dropping in the entire 500 engine/Turbo 400 transmission assembly out of a mid-70's Cadillac Fleetwood would be a very simple swap. Just fabricate some motor mounts or adapt what's already there, and get a set of pipes made at a muffler shop. The big GMC V-6 was an overweight gas guzzler with a very poor power to weight ratio when it was new, and 40 years later, it hasn't improved at all!
Jerry
