My '50 3100 came with a full pressure 235, a mid sixties Saginaw 3 speed, and 3.08 rear end gears. In first gear, it could not get out of its own way on a hill, or if one rear tire was in a slight depression. It did go down the road nicely at 60+ miles an hour, but getting to that speed
with that setup involved lugging the engine in first gear and then mashing the gas until the engine was screaming right before the next shift where in again lugged. This process continued through 3rd gear.
I couldn't live like that anymore, so I went with a T-5 with .72 overdrive and a rear end out of a 2001 Nissan Xterra. That rear end is basically a Dana/spicer rear end. It was limited slip as well. The gear ratio is 4.64 to 1, which I was afraid would be too high, but with the .72 overdrive 5th gear, it worked out very well. I did go with 215/85-16 tires (30.5") in place of the stock 28" tires and that dialed everything it for me. It is an absolute dream to drive. I want to race people with it. I can pull stumps and drag them down the road at 70 miles an hour.
I have not done that yet, but I swear I am going to do that one day. I need to call the YouTube right before I do it so that they can send their camera crew out to film it. I guess that's how it works...
Have you used that RPM/tire height/rear end gear calculator to verify what your RPM is with what you have and what it will be with taller tires? Hopefully someone will come along soon and provide a link to that calculator.
