VTRover-
This is from another related post but maybe you'll find it helpful.
Maybe you've already fixed the problem but I used the Delco 10SI, part # 334-2113. It puts out 63 amps. I actually had to do a generator to alt conversion. Had to fab some new brackets but it was all pretty straight forward. Another Delco alt that should work is #321-250, 12SI, which puts out 78 amps. It is nice knowing that I can probably find this part on the shelf if/when I need one.
Jeff
1964 Series 2A SW, LHD mostly stock, often runs!
1991 Range Rover Hunter