Amp gauge shunt

The reason for the thread was to find out if anyone copied the factories solution of a increased amp alternator installation in an a-body. My main concern with any wiring modification is fire, already watched one car burn to the ground due to a failed Pertronics ignition module. I'm not married to my 50 year old amp guage, just looks like a simple fix. Probably going to run hot 6ga wire from a insulated terminal block wired directly to starter relay/alternator to another insulated terminal block under the dash. Then eliminate the under dash splice and gut my amp guage and do the Sunpro volt guage modification on the ralley gauge. Just want do it right the first time.