Might be old news but if you need a 24 volt alternator and also want 12 volts for a few accessories the Delco SI series work great. I recently bought an M-37 and it has one in it. There are many sizes up to 160 amps. They bolt in with few problems and its just one connection to the battery. And, there is a 12 volt terminal if you want 12 volt accessories. For the '715 I don't know about the 3 belt pulley fitting but I have been told there is probably one that will fit at the supplier.