67 Dart-upgraded alternator

You'll already doubled the amps The your wiring harness was built for.
If you compair the wiring in your 67 to the wiring in later models you'll find differences in wire gauge, especially the drk. blue w/white. That wire is passing more current through your ignition switch now.
Fast forward to todays vehicles with their high amp charging systems and you wont find many long lengths of heavy gauge wires but you will find it where it is required along with a gallon bucket full of fuses and relays to protect those smaller wires.
While no alternater is going to supply more current that is required under normal conditions, a short circuit, undersixed or worn contacts in switches or connectors are fore starters.