As Tim posted it's always helpful to know what year vehicle you have. But since you indicated that it has been converted to 12 volts it could be pre 55. First series 55 trucks were 6 volt with an open driveline. Second series 55 trucks are all 12 volt. Since pre 55 trucks have an enclosed driveline an overdrive transmission cannot be used in your truck without changing to an open driveline rear end. An overdrive transmission conversion is a good option to make older vehicles perform better on the highway.
Fred
Last edited by rfs56trk; 02/25/2015 5:57 PM.
