It is not true that ALL Chevrolet trucks are negative ground. First run 1941 Military trucks are 25 amp positive ground.

[img]http://www.surfacezero.com/g503/data/3764/medium/2014-07-12_09_21_34.jpg[/img]


1941 Chevy 1 1/2-ton WW2 4x4 dump truck
In the Stovebolt Gallery
Lots more pictures