I think people over complicate it, make sure you have good wires and conectors and a decent altenator won't discharge at idle.

My 68 cuda always dimmed the lights for the last 2 years at idle till the original altenator died a couple months ago. I installed an altenator for a 75 chrysler from oreilley auto parts and at the same time put on a VR from NAPA that was listed for my car, I soldered new conectors on instead of the factory clamp on junk now it no longer discharges at idle with the engine fan full speed, heater fan on high, brake lights and head lights on and electronic ignition running at 800 rpm idle. There is a second field wire on the newer altenator just find a good ground and make a good wire to go to it.

If I needed more I would upgrade to the denso altenator, way more reliable and puts out lots of amps at very low RPM