Harvester,
The engine is a ca.1978-80 with a early 70's points distributor, so it is 12 volt negative. You are correct though, the truck from the factory should be 6 volt positive (for which it once again will be when I am done).
I haven't had the opportuntiy to progess further as we are experiencing snow/wind from Sandy. I will investigate further this weekend when the weather is more hospitable.
Paul
