Floor shift conversions have been used for years and are available for 3 and 4 speeds. The OD on the Saginaw is contained in a special tail housing on some 3 speeds. It is activated by an electric solenoid and a governor system. That three speed uses the same case as the Saginaw 4 speed so the OD can be put on the 4 speed. That gives you 5 speeds or 8 if you want to play with it. All of the older standard transmissions had a 1 to 1 ratio in high gear whether 3 or 4 speed. The 4 speed usually just makes the ratios closer between low and high and allows you to use the engines power band more efficiently. They can help turn a quicker 1/4 mile if you can shift. There were some close ratio 3 speeds that were pretty quick. The ODs are usually about .70 to 1 which either reduces engine RPMs by 30 percent at a given speed or raises speed by 30 percent at a given RPM. In the late 60s the Saginaw 3 and 4 speeds were all the same length even if the 3 speed was OD. They will bolt into your car. The 3 speed OD would use your column linkage. It might even be possible to shift a 4 speed from the tree if you shifted reverse separately.(sort of a pain) Some people lay much praise on Muncie 4 speeds. They are lighter, more expensive, and somewhat stronger. No trans will stand up to constant abuse. I ran a hot Olds in front of an early Ford drive train and eventually learned to drive it. It was a hand full. I hope this helps. I think it's mostly true. \:D Beater

"I wonder if God created man because he was disappointed in the monkey?" Mark Twain