GMC1937 -
Your truck is basically a 1937 Chevrolet 1/2 ton pickup with a GMC badge on it. I have a 1937 Chevrolet 1/2 ton pickup. Here's is what I have done. I have a 55 Chevrolet car rear end under the truck. It is 60 1/4" wide and fits perfect. It is a Power Glide rear end with a 3:54 to 1 ratio. Your emergency brake cables will hook right up to the 55 car rear end with a little garage engineering and patience. A 53-55 Chevrolet or GMC truck front axle will bolt right under the truck with no modifications. The advantage over your original axle is that is more heavy, has the larger king pins and is set up to accept 50-54 Chevrolet car backing plates and hubs. These backing plates and hubs along with the 55 Chevrolet car rear axle will put you on the street with five lug wheels all the way around, Bendix brakes and an open drive line. You probably already knew that. Couple that with a dual master cylinder and you be able to stop with the best of them. Remember, you gotta be able to stop before before you can think about going!
A T-5 is a very good choice. With an adapter, you can run a T-5 and your can cruise at 65-70 easily. I had mine up to 80 a few weeks ago. That was scary!!
All in all, it is possible to bring your truck from the late 30's to the mid 50's without very much effort and you will gain a bunch! There is some effort, especially setting up the open drive line rear end, but it is worth it. The rest of it is just a matter of doing it.
Joe
