Not sure what you have remaining on the car from the original wiring.
This will give you some idea of the original scheme.
Ignore the voltage regulator etc at the top since yours is internal and its irrelevant anyway.
Some wire colors and sizes may be different in '70 but otherwise circuits should be right.
The headlights themselves got power from the main splice. Their circuit breaker was in the headlight switch.
The parking lights got power from the hot side of the fusebox. They shared the fuse with dome light and the brake light.
The lowest draw regular lamps are a cheap set of halogen sealed beams. Low beam power draw will be rated 35 Watt.
LED should draw less but I don't know what the weight is with the heatsink etc.
If you want lightweight sealed beam or H4 type, send a PM to
@CPDave and ask what he's using on the Dart for similar purpose.
PS. You can see in the diagram some of the problem with the original circuit, especially when the higher wattage lamps came along around '72 or '73.
Only the A-bodies got 18 gage wires and 15 amp breakers. My only guess is it was because that's was suffient for the 'compacts' when sealed beams were only 40W/50W.
