1970 Dart - Single-Wire Alternator Conversion
Personally I do NOT care for "one wire" setups. The require abnormally large charge wires, which can be quite large for trunk mount setups. The voltage drop of the charge wire when using an external regulator or a "3 wire" integral is not nearly so important, because when wired properly, the "sens" wire feeds from battery to regulator---which keeps the battery voltage proper, regardless of drop in the charge wire.
External or "3 wire" setups can also be much easier to deal with with trunk mount, where you need a disconnect system "on race day."
Without some expensive "load dump device" for disconnect, I know of no good way to protect the alternator / system from spikes in a disconnect while running situation, using a one wire alternator. Some racers insist on running the charge wire direct from alternator to battery. THIS DOES NOT RESULT in a disconnect. YOU are the guy who will be hanging upside down in the belts with fuel pouring all over, and that hot charge wire ready to weld away. Think about it.