I believe GMC held on to 6 volt one more year than Chevy did. Weren't they Positive ground too? Pull a bulb and check the numbers on them. Think a dash bulb of 55 is 6, or back of headlight should say voltage if you pop one out. Generator tag sometimes says? OR color of it means something.


G.L. Grumpy's
Old Iron Ranch
Huntington, IN 46750


MM R tractor, Speedex
and Power King tractors