Only Chrysler alternator performance curve I've seen is the one Nacho got in a box with a revised squareback ( IIRC).

https://board.moparts.org/ubbthread...stem-upgrades-73-e-body.html#Post2609330

Notice the test voltage was 13.2 V
So can't compare directly to test in the shop manual.
Assuming magnetic field is a strong as it can get, the we could calculate the power at 1250 engine rpm if we know the pulley ratio.
P = I x V
Then divide by 15 voltage to ge the current it probably would produce at the higher voltage.