A Tahoe frame would be too short, and would also interfere with the door steps. The '73-'87 would be better, even then there's a wheelbase issue (114 vs 117). Avoit the Toyota, thet're bad about rusting apart at the rear cab mount (Toyota had BIG recall on that).
Best bet, though, to keep everthing properly lines up and fitting right, would be to convert the stock frame. Since the stock frame is already leaf spring, it's not really a big issue to install drive axles on the stock frame. Check out the Napco trucks, which was a conversion. If you can find it, 4 Wheel & Off Road did a buildup of a '57 shortbed back in the late '80s, Project Early Iron. They kept the stock frame, but used all the running gear from a later GM truck.
