Alt advice

The solution that 6pk2goDemon mentioned is the best way to get rid of the horrible voltage drop that the factory 18 gauge headlight wiring provides, not to mention two passes through the bulkhead. It also get the headlight load off the bulkhead and ammeter.

Get rid of that insufficient wiring and you'll have a much better lighting experience.

Rice Nuker hit on the other, alt rpm is an issue with factory mopar alternators. I don't recall the max RPM on a mopar alt, I run the densos to a max of about 18K. You could always put a smaller pulley on your mopar alternator to increase alt idle RPM speed which should help output. Don't over run the max alt rpm limit.

An alternator only needs as much capacity as the system is going to draw. I usually size them for max amp draw +5