zoegrant,
I was just responding to information you provided. mechanic58 posted a photo of a transmission that was used on a vehicle with an open driveline.
Your response was "yes..your picture looks exactly like what I have." Then you state later that you have a torque tube.
Perhaps someone can identify your transmission from the numbers, I don't know.
However, If you have an original truck with a torque tube and a 3 speed transmission, it uses the same unit from 1948 through 54.
The transmission mechanic58 posted is not correct for your truck.
The standard 3 speed (open driveshaft) transmission used from 55 through 67 is an SM318. I have seen the previous version (48-54) referred to on this site as an SM318 also.
I cannot confirm or deny that this is correct for your series.
One thing is for certain they do not interchange. The case is different and the internal components are different also.
Fred
Last edited by rfs56trk; 01/08/2017 1:30 AM.