I have a '50 with a '53 full pressure Blue Flame 235. It came with a 3.08 rear end and a Saginaw 3 on the tree.
It was great on the highway, but horrible in first (couldn't get out of its own way).
I switched to a T-5 from a mid 80s S-10 which had a 4 cylinder.
I also added a 4.64:1 limited slip rear end out of a 2001 Nissan Xterra. (A very simple swap, BTW.)
I now have an unbelievable truck to do whatever I need it to do!
I can climb up a wall, or cruise comfortably at 65 MPH. Shifts are as smooth as butter, and you will find that with the extra 2 gears, you will constantly be in the optimal power band of the 235.
You likely have 3.90 rear end gears. The T-5 which I mentioned above would be a perfect option for you. There is an adapter plate available which makes this swap easy.
Search this site for "Lugnutz T-5 swap". Lots of good info on his website.
Carl
