Excellent info. A couple of notes: VATS disable is your friend. The crank relearn is NOT necessary unless a P1336 or P0315 code is thrown. (Yes, I know there are those out there who think it's required, but GM's own documentation says it MAY be required.) Reflashing the stock PCM should never require a crank relearn, so if possible always use the same PCM the crank sensor was paired with at the factory. You MUST set the parking brake! (I'm not sure where the signal for this comes from, but I do know the crank relearn will fail if you don't set it.)