http://www.alternatorparts.com/ford-f-series-truck-high-output-alternator.htmlNew Ford F-Series Truck High Output Alternator Page
In 1973 Ford started using their first generation of alternators. Dubbed the 1G, this alternator was externally regulated in amperes ranging from 40-65 Amps. The 1G was in service on the F-Series truck until about 1992. It was later replaced by the 2G series alternator from 1986 to 1992, the 2G is not upgradeable to a higher output because of its weak bridge rectifier and the power plug can catch on fire from the higher amperage load. The best high output upgrade for the early 1G series alternator and the 2G series alternator is the Ford type 3G series alternator
