What amp is the alternator?

Well if you can find a shop that will load test it, have them tell you the load (in amps), and voltage at 1250 rpm.
If they give you the amps at other rpms and voltages, great, write that down too.
With the max load and the voltage at 1250, can calculate the power. From that calculate amps at 15 V to where it falls in Chrysler's specs.

For the pulley, thats maybe even more important to be sure its the correct one in that its matched to the crank pulley. If it turns too slow it won't produce much if any power at idle.

Assming all good,' then ground the second brush.
Something like this will work.
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