The engine you are describing sound like the industrial version found in the F-600 and up size trucks and would most likely be a 33, 361, or 391. These engines come with a steel crank, and different heads than a standard 360 or 390. If you look at the heads there should be a couple of bolts right in the middle of the head also, as there is a fifth or common ( I'm not sure ) exhaust port in the center. I have a similar moto in my 70 f-600. It's not a real screamer and it's a little hard to find parts for, but the truck and the motor are in good shape. I would find a car or truck 390 to use in your project truck just for ease of operation and parts availability. Hope this helps!! ( the 477 and 534 blocks are waaayy different JUst fyi)