i just put a 2001 3.0 motor in my 1987 boat, it has est distributor, it came without the connector in the icm module to set the timing, i have a regular gm connector to plug in there. i had a guy tell me that has the timing connector which wires on my connector are the same, if you are pluged into the distributor the wire all the way left is not used and the next one to that is your 12volts and the other 2 get hooked together to set base timing. i have tried to put it in base timing mode while the engine is running and it stays where i have it at 12 btdc. i dont think i have to put the shift interupt wires together because it isnt hooked to this plug, i think hooking them together just puts 12 volts to the plug anyway. i would appreciate input on this thank you