This 1997 Vortec 5.7 was towed in for a cranks no start condition. Testing leads to a failed ignition coil, leaking to ground under a load. Replaced coil, distributor cap and rotor as well as a set of plugs. Starts and seems to run fine at first then the forward O2 sensors are acting strange. I ended up putting a used PCM in the truck and programming it as required. Still has other issues.