Hawker7 The cheapest and simplest way to convert to a single wire internal regulator alternator and maintaining the stock wiring harness is to use converter kit. But first you have to identify the alternator type that you will be using (see attached picture).
Normally if you are going to buy an alternator to replace the stock one with a single wire it would be an SI
For CS Alternators use part #37787 converter kit by M&H Electric Fabricators
For SI Alternators use part #27555 converter kit by M&H Electric Fabricators
Converter kits can be found at (
http://www.wiringharness.com/ ) use the search function or contact Wess at Classic Heartbeat Pickup Parts (
http://www.classicheartbeat.com/default.htm ) site supporter.
Hope this helps