Basic 318 info needed
The 1972 3/4 ton block may have a steel crank and thicker cylinders. I've got two truck 1973 half ton truck 318's, and one has industrial thickness cylinders and the other doesn't, YRMV. The '88 half ton engine should be a hydraulic roller engine with 302 fast burn heads and close to 9:1 compression. If it does have the hydraulic roller cam, send it to Ken Heard at Oregon cam grinders for a regrind. You'll need a 318 car type pan for it, but as noted, the pickup out of the 360 will work. I would look into the 3/4 ton block a little closer. If it has a steel crank and you have any plans for a fairly hot small block, hang onto it. Chances are good it could go .090 over (4.00 inch bore) if it has a steel crank.