Ok, so its taken me two years to almost complete my LT1/ 4l60E conversion. I fired it up for the first time the other day and it wouldnt turn off. I pulled the battery cable, kept running. Pulled the Alternator wire and it died.

OK so i figured the diode Ihad put in the wire from the alternator to the ignition must have been backwards. I open up hte harness and flip flop the diode. Car starts and will not turn off. I pull the battery cable and the car dies this time.

So I must have had the diode backwards the first time, but what else have I wired incorrectly to make it keep running with the key off?

Sounds like you might have your ignition circuit connected to a source that is hot all the time.

Well with a test light it shows to only be hot when the key is in the run or start positions.

Seems to be some back-feeding from the other wires in the ign plug as you probavly had the connector unplug from the dist to make the measurement.
Back probe, if you can, the connected dist connector with ign off and see where the power is coming from. I think in OE LT-1 set-up, the PCM has a power relay opening up during off time to kill ancillary power.

Ok so I got it figured out. I created my own problem because i assumed what a wire did. I mounted my computer in the trunk so i have a long harness. There was a wire in the harness that runs from the computer to the front of the car. The wire was labeled power to fuel pump. Well I thought i would shorten the length of the wire, so i cut it and ran it to a constant power junction block in the trunk, which worked fine. Then I got the great idea of powering my igniton from the junction box on the firewall. I decided to use a butt connector on the before mentioned cut wire, which I thought was just a through wire, and then tied it into the junction box on the firewall. Well come to find out, the power to fuel pump wire, recieves a positive feed from the oil pressure switch. The oil pressure switch serves as a backup system for the fuel pump in the event the fuel pump relay should fell. Any time oil pressure is above 5lbs, 12 volts are porvided to the to the fuel pump.

So what was happening was once the car started, the ignition wire was recieveing voltage from two sources. I would turn of the key killing one source but the oil pressure sending unit would continue to send 12 volts to the computer.

So lesson to be learned here:
1. Never assume anything, it always makes a a** of u and me.
2. Dont muck with someone elses wiring harness.

Aha! Good thinking! I hate assuming.