Voltage regulator problem with 1968 Dart

Sounds like that was done correctly.
Do the checks 67Dart273 suggested. Don't need the battery connected.

Not sure why the 6 gage wire goes from alternator to the battery in the trunk.
Simplest method for battery in trunk is battery positive to starter - but larger than 6 because of the distance- then 8 or 10 gage up to the starter relay.
Everything else is factory and will work and trouble shoot same way.
(this is assuming no kill switch.)