I look at it this way. Power to start your truck is calculated as volts time amps. A 12 volt battery with 500 cold cranking amps has twice the power a 6 volt battery with the same cold cranking amperage rating does.
I run 12 volts in my Chevy but think I will keep my GMC 6. I can understand some people want the oringal sound of the 6 volt starter and horn.
