Insulate, wrap it well, and wire tie it to the harness. I use about a three and a half inch piece of large heat shrink tube used for battery cables. Stick that plug about halfway in, apply heat to shrink the tube. Fold over the remaining piece. Wrap it well with electrical tape directly to the harness.
Sounds like you have something else going on. Did you use genuine GM or ACDelco for the camshaft and crankshaft sensors? (Really need to use OEM on all sensors, aftermarkets have a long history of being erratic) With that said, even aftermarket sensors would not prevent it from cranking over. You might start by unplugging the starter wire from the ignition at the starter. (Not the battery cable, the smaller wire that triggers the starter) Check it for voltage when you turn the key. From under the vehicle, if you reach up under the right front wheel well and over the frame rail, you can reach in and unplug it. As a side note make sure you have that metal heat shield snapped on the top of the solenoid or that starter won't last long. Then start tracing back through your electrical system. You might also double check your ECM plugs, make sure they're both locked in tight.
