My 55 Sunliner is set up for a Ford external regulated alternator and has anyone installed one using the generator brackets,seen kits for a GM alternator but do not want to change it.
I think it may prove easier to remake the upper 'U' bracket specifically for the alternator but using the same block attachment point. The generator adjustment bracket should work as-is with some tweaking possibly needed.
Something like this Adjust length as needed to get belt alignment, use spacers if needed for the water pump bracket. I'd use stout material, 1/4" flat stock at a minimum. Weld the tapped boss onto the end.
I hung a alternator on the other Y block I have and the one bracket will need to be spaced out from the water pump and will need a two groove pulley,now the brackets on the 292 I am going to be installing have that bracket spaced out from the water pump and the other bracket has been modified so time to remove the generator and see how it fits.