Since the LT1 stopped last November I have replaced fuses, relays, ignition module, ignition coil, and distributor. The engine did NOT throw a code. I obtained a CPU from a donor vehicle. I was advised that I would need the chip from the ignition key of the donor vehicle. While swapping the CPU I noticed some green corrosion on one of the 128 wires on the CPU. I cut into the harness and found a section of wire that was discontinuous. I spliced a new piece of wire. The engine runs fine. One wire in 128 killed the entire engine. I find it interesting that I used my ignition key with a CPU from another car. I wonder if the anti theft chip really works. I have another GM vehicle that has an ignition key with a chip. I had a non chip key cut and it starts the car OK. Thanks for all the advise.