Houston54,
In your situation, I'd buy a 12v motor. I have two of the 6v motors but I am reluctant to install them in my 54 trucks. You need to drill two holes through the dash to hold the GM accessory 6v wiper motor in place. Two screw heads then show on the top of the dash. The 12v motor is a "clean install" as far as leaving any visible evidence.
Tim
