The early 6 volt truck starters and later 12 volt truck starters took different drives. 6 volt starter armatures had straight spline shafts and the later 12 volt starters had twisted splines. The teeth on the gear were different as well. It is possible however to replace the drives with different ones. Example: you have a late style 50s 12 volt starter and want to install it on your late 40s truck. I can supply a drive that will be twisted on the armature shaft but have the gear from the late 40s starter drive. Its making a starter that never existed and a little of a custom job but it can be done. Starter modifications like this allow you to keep the original flywheel.

Last edited by Kennethw; 04/15/2014 8:19 PM.