any big, or smallblock should bolt up, as the truck has side motor mounts. the final ratio of the trans is 1:1. or direct, unless it was a special order, or has been rebuilt to overdrive. (yes, you can do that with the 5 speed).
i think the doors and some cab parts will interchange.
the rating of the truck depends on the way the suspension is set up. yes, there are certain specific capacity values for the 100, but guys had a habit of adding leaf springs, etc., to increase the capacity.
ought to make a killer tow truck.
just missed one locally that was set up with a 500 holmes on it. they cut it up.
