I'm just the gardener so I won't give mechanical advice. As the gardener I've seen the Detroit, Cummins and most recently the Duramax wedged above the Early Deuce pumpkin. The biggest challenge has been the upper link for the front dif that gets in the way of everything. The second challenge is width between the frame rails. The third challenge would be mating a 50's transmission to a diesel. There's that nuisance control valve on the side of the hydramatic that is throttle controlled. I don't know about mating but I am saying anything can be done as long as it's done in the garden.
I do know a fella that shaved the head on his 302 which gave him some more muscle. The original M211 is valuable in a lot of folks minds so there's always that option of selling the 211 and jumping in one of those 900 series automatics. There's a diesel / automatic match that's hard to beat.
