amp gauge???
DO IT...I had a VERY bad electrical melt down on my way home from Carlisle... Had my Dart roll backed almost 60 miles to my house. I ended up removing my windsheild and steering column to remove the dash to work on it easier. Then, spent a week cutting apart wires with a razor blade and replacing wires.
If you do this, and I talked to this guy...don't splice the heavier wire to the 12 gauge wire coming off the alternator. Run 10 gauge wire right off the alternator and run it right to the starter relay. Solder EVERYTHING and insulate well.
You won't regret it!
I also did the the headlight upgrade from Painless. Between the two, what a difference. Any questions shoot me a PM.