Hi KLM. I'm in Atlanta, too. I have a '46 1/2 ton with a '54 235 in it and 3:55 ring and pinion. If you'd like to go for a ride sometime give me a shout. A bit earlier truck than what you're considering, but it might be useful to you. You've got to have a few more posts before you can PM me, though.
Nobody has mentioned the low pressure 216 vs the full pressure 235 comparison. The older engine in Chevys (up to '53 Powerglide and '54 all) had a low pressure oil system (you'll see a 30 lb. gauge on the dash). The truck you're contemplating would have this. Not sure what year they went away from babbit bearings and splasher oiling, but they had that, too. In the '53 Powerglide car and all '54s they went to what's called a full pressure system (60 lb. gauge on the dash). These had insert bearings. This is important if you need to rebuild an engine as the 216's are tougher to find a competent rebuilder - lost art. The '54 235 is the holy grail for engine swaps for an older truck as it is a straight bolt-in (provided it's truck engine). My engine came out of a '54 Powerglide car and had to have front motor mounts modified to fit the truck.
The full pressure engines have more horsepower and (I'm told) last better than the 216's. Mine was rebuilt in 1986 and now has about 70,000 miles on it. Good runner, no smoking or oil burning.
This is meaningless if you get a GMC - the 228 was full pressure during the years you're considering. Completely different engine. Much superior to the 216 in my opinion.
Another thing to consider is that Chevy went to Bendix brakes in '51. They are superior to the Huck brakes used in '50 and before. That said, I've got Huck brakes on my '46 and they do fine. I've done Bendix brakes on a '51 before and that system is superior - easier to adjust and better brake action.
My 2 cents
