Are you asking about a Powermaster alternator that looks like a generator?
If all you care about is changing to a alternator, I also used the bracket from a 1963 215. Both a 12SI and a CS130 will fit this bracket with no mods. I swapped the pulley from the generator onto the CS130. Use the CS130 from a 1988-1990 Cadillac Fleetwood with the Olds 307 motor, which has the correct mounting ears and is 105 amps.