Good save on the GMC.
It seems about 95% of the time when I see a nice '60 to '66 1/2 Ton for sale, it will have a 3-Speed. I love to see a Granny Gear 4-Speed in 1/2 Ton. I've even had the problem of finding 3/4 Ton's with a 3-Speed. I usually pass on those. Switching over would really be no problem except for the Floor Hump. That usually stops me from proceeding on it. If I switch mine over, I'll most likely go with a car 4-Speed with a low first.
Bill
Ive changed a few over from collum shift to granny low 4 speed. the problem with me is the drive shafts. truck 4 speeds need a slip yoke drive shaft and a center carrier bearing. Im thinking about installing a 73 up front and rear on this newly aquired trucks frame and swapping on a better cab & bed.
