Here comes information on my wiring.
Tachometer (RPM Rev Counter)
Originally the signal to the tachometer came from the coil(-), but since I'm now using 4 COPS (instead of 1 coil from the original distributor setup) I need a different tachometer signal. A possible solution is to wire signal from each coil with separation diodes into the cars original wiring to feed the tachometer, shiftlight and fuel pump relay. Why don't you control the shiftlight and fuel pump relay directly from the ECM ? Using 4 high-voltage diodes (such as ES2J or BY399 or even 1n4007) to make a tach signal compatible with the original sounds good.
A similar sollution is described at the bottom of this page http://www.megasquirt.info/ms2/EDIS.htm