I would guess that the T5 would make it seem like a modern truck with 5 gears. It would be nice and easy to shift. I have a sm420 in my '59 and most women and kids can't even drive it. I like it. I like winding it out in third and I like the granny gear. I really like the super low reverse. The T5 would definitely be an upgrade but so would a new Silverado. I guess I just like the old everything. I bet that didn't help you a bit.
Ps. If your original transmission is a three speed, almost anything would be a tremendous upgrade!
Last edited by GeneWiseman; 11/22/2017 2:41 PM.