Experiment with a T-Bird? Why not !!
The hot rod standards that I have seen most used are first of all, the Jag then next is the 'vette. Both are excellant choices.
The T-Birds are based on Ford's 8.8 differential that is used in almost everything from a Mustang to Lincoln and F150s. I've only seen a couple of the T-Birds modified for street rod use, but there are plenty of rear ends around, cheap (well, within reason) with parts that are easily found at any NAPA. My experience with the T-Bird has been mixed. My '94 had seal problems forever and the dealer warranty was "evergreen" in that I never let him let it run out. The '97 was a Equalock, with disc brakes and trouble free. Unfortunately, stock, they aren't too pretty and dress up parts may not be easily available(yet) plus they are w-i-d-e.
Most other IRS from 4 and V6 imports will never hold up under American V8 horsepower.