62 F250 4X4 Transmission Conversion

[62unibodymatt]

I just bought a 1962 F250 4X4 in great shape. Has a 390FE, T-18 w/granny low, and the divorced transfer case. I'm looking for an older 5 spd heavy duty transmission to replace the 4 spd thats in the truck. Does anyone know of a particular transmission I can bolt up to the 390 and get some overdrive action? The DANA 44 axles are geared with 4.55's and the engine is screaming at 50mph. I have 245/75R16 LT on now, but will upgrade to bigger tires soon. Any recommendations are appreciated. Thanks