Yeah, I know... my '59 was the same way. I was afraid I would warp the cab if I lifted it with 2x4's so never got to that point with my truck.
When I took the body off of the frame on my Corvette restoration, I rigged mover's straps (2) under the body hard points, and lifted it straight up with a chain hoist........built a frame out of 2 x 4's, with industrial casters on it, and after removal of the rolling chassis, lowered the body onto the homemade carriage.
The cab on that pickup, with nothing in it, likely doesn't weigh 300 pounds.....a guy on each corner should be able to pick it up easily......they are a welded assembly, and pretty rigid. I was much more worried about cracking the fiberglass on the Corvette.
doc