The original wiring is that a white wire goes to the + or no 30 side of the coil, white/black goes tot he - or no 15 side of the coil, on this - side there will be 2 wires, 1 for the dizzy and 1 for the tacho. with the new distributor there should be a wiring diagram that will tell you what to connect where. BTW didn't the old Lucas amplifier had 3 wires coming out of the dizzy ? i would not cut the old loom but open it to see what you can delete and what u can reuse.