The 4 wire plug is for the ESC system with the computer that adjusts the timing to retard spark knock. It will not be used with a swapped in distributor for a non-computer application. Also, if you want an HEI, it is not a points style distributor. It is a solid state electronic ignition, which is far superior to a points style ignition found on pre-1974 GM cars and trucks. If you want a points distributor, don't forget to use a ballast resistor as the points can't handle a full 12 volts and will burn out quickly without it. The ballast will cut it to 5 volts, if memory serves. If you want an HEI, everything will plug right in to your current wiring. There are only 2 wires that plug in to the HEI, one is switched ignition power and is pink, the other is white and is used for the tach. The tach wire is not necessary, but the switched ignition is. The HEI is one of those glorious GM electronic things from the 70's that is super-simple to wire, just like the 10si and 12si alternators.
