I used the yoke for a T-350 on my Saginaw 4 speed;they're easy to get.
The Saginaws came with more than one first gear ratio-there's information on how to identify the different ratios on Stovebolt;you should be able to find it by doing a search.
I also discovered you need to watch the tailshaft housings on the Saginaws;I have one set up with a shifter,and two of 'em that don't have the bolt holes to mount a shifter. Apparently,these were used in GM cars with the shifters bolted to the floor,instead of the tranny. If you get the tranny and the shifter that goes with it,you should have no trouble making it work. It's a good choice.
Speed