As posted, the factory made them up to 78 amps. Powermaster sells a 75 A. Other aftermarket folks push them to 100 amps (eg. Tuff Stuff).

On all of these the idle output is max 50 amps, sometimes less. No matter what you do with the the small case Chrysler alternator, idle output is limited. If you are stuck in traffic and need your fans, the alternator probably won't keep up unless you rev up the engine.

I think you would be better off with a GM style alternator (Powermaster or other) or a Denso. Or get a bracket for the big frame Chrysler alternator from the mid/late 70's. 100+ amps with little drop in output at idle. It was used on heavily optioned Cordoba's and some other models.