My 4bt from a 1988 Ford 3/4 ton bread truck is a CPL# 858. It has the Ford charging system on it (autolight?). It has been rebuilt and I think the case was cleaned in a tumbler type cleaner and it must have wore off the markings. I can just barely make out the field and stater markings. I have removed the alt and looked it over real close and still can not find the amp rating on it anywhere. the case is 6.5 in in dia. and about 4 in deep. I suspect it is around 100 amp. How common is it and does any other Ford product use it?