Another way to go is use a Saginaw all synchro 3 spd. with an overdrive. I see these all the time a swap meets cheep. I put one in a 53 car and it worked good, I have also put the o/d on a Saginaw 4spd. I have a friend that did the 3spd.o/d in a 51 pickup with a 261, what a sweet driver it has the kick down and oem column shift.
Jay D.