The only trucks that used the floor starter where the manual transmission 6 cylinder. Hydramatic 6 cylinders and V8 trucks used a solenoid type starter. They also use a different ignition switch that has a "start" position. The floor starter is not compatible with the V8 bellhousing.
Side note, the '57 1/2-1 1/2 tons did not have a 283 option. They still used the 265. The 283 wasn't offered in the lighter trucks until '58.


Bill Burmeister