(sorry no part number)the generator that I used is used on a 1980 Pontiac Bonneville with a 350 engine it is a 10si GM alternator the only one that is as common as the 10si is the 12si these parts are common and they are used for multiple applications tractors, industrial machines, etc. As for the external alternator no I did not use it this one has one inside so we bypassed it. if you want to know what we did pm me and I will send pictures of it. with descriptions the difference being is that we moved it from the bottom left to the upper right we went from 55 amps to 63 amps. GM did make this alternator right it was used from 1973-1993 Bottom line it is reliabe most parts houses have them is works better than the old one EVER did