Matt, you got me interested, so I did a little research, turns out these cars had either the C50 or C52 tranny in them. Well the C52 is the stronger of the two, and was also installed in the early Corolla GT-S, where it was equipt. with a 4.37 final drive gear. While these two cars are totally different in layout, the final drive gears can be removed from the Corolla box and installed in the MR2s
Happy hunting, Bob