Why not try unfreezing the original engine, it may be a stuck clutch. Squirt a little oil overnight in each cylinder, add new points, clean the carb, clean the cap, change the oil, check the ebrake for proper working order in case you do get it started, a little starting fluid, fresh battery, put it in second or third gear and a gentle pull with another truck (that's why you need brakes) at least you can drive it around the driveway instead of pushing it when you start the rebuild project. I have gotten engines to run that sat for many years in about thirty minutes. I like the challenge
.......g
