I found a T85N 3 speed overdrive for sale. Says it has a R11 tailshaft and that it is out of a ford vehicle from the mid to late 60's. Will this work in my 59 Apache 3200 to replace the old 3 speed Saginaw? Or do I need something totaly different?

1959 Apache 3200, Standard Cab, Big Window, Fleetside, 235/3spd, Original Paint
1964 C20 Standard Cab, Fleetside, 283/Power Glide, A/C, Pwr Steering, Pwr Brakes, NoSpin