5.7 HEMI Alternator ?

Most (maybe all) of these late model Mopar alts. still have 2 field terminals. Some test equipment manufacturers make an on car tester that is just a regulator inside a box. It works by disconnecting the field terminals from the alternator to isolate it from the computer and then plugging in the tester. The tester is wired exactly like the standard Mopar electronic regulator setup (battery voltage on one terminal and the regulator on the other). You could try wiring it up with a stock regulator and see what it does.