[burnin oil]

The Saginaw 4spd car transmission was also an option. I have seen it once. That said the 3spd and 4spd saginaws shared a common case and main shaft. Different gears and side cover/shifter. So if you find a base model 6 cylinder column shift you can rob the 3spd and rebuild it installing the 4spd gears on the original main shaft. neither are terribly expensive and pretty cheap to rebuild if it breaks. The 1974 or 1977 chevy service manual actually has pictures of all the factory adapter plates and which transmissions and transfer cases that they fit. Obviously these are pre round pattern, 5spd, or alum transfer cases.

For fun I have run (still own it sitting in the barn) a 465 to NP203 factory adapter. that was a real nice setup if you lived in an area that had alot of black ice during the winter.