When you're upgrading from 6 to 12 volts, it's worth remembering that your new 12v alternator delivers twice as much power per amp charge as your 6v generator did. A 65A 12V alternator delivers 780 watts, you'd need a 130 amp 6V generator to deliver the same power.
Alternators and generators are always quoted in terms of amps output, but it's the wattage that powers the electrical systems on your truck. The wattage demand won't change much unless you fit some power hungry accesories while you're going from 6 to 12 volts.
Stuart.
Last edited by Stuart_Giles; 03/22/2010 10:44 AM. Reason: typo.