As luck would have it. last summer my voltage regulator had started making funny noises, so I took it and the generator in to the old pro in town. He made some adjustments ( I don't remember what they were), and said it was working fine now. I know he looked up my truck in his manual to make sure I had a 6 volt negative ground system. So I figure he adjusted the voltage regulator down from whatever it was set for that 8 volt battery to what would be correct for a 6 volt battery.
Today I checked the voltage between the regulator's field terminal and the ground and got 8.5 volts. Is that high enough that I need to take it back to him for adjustment?