OK, so byte 819C is already in the XDF as the "N/V (tach/speedometer vss) ratio to use WOT Disable", and the stock F-body bin it's 36, in the stock L-body bin it's 101. Byte 819D isn't defined in the XDF yet, so what I will be doing is adding it as a new scalar, naming it "Possibly the MAP value to disable the A/C", and I will play with it to confirm if that's it or not.