Hi Adam, congrats on the SC mods.
I found a threaded bolt hole in the rear of the passengers side head, just by the coolant ways. Besides being one of the only places suitable for me, I understand water has good accoustic properties to carry detonation vibes to the sensor. As you went with the Paxton, see if you could use the bolt for the coil packs bracket, in the rear center of the 'V' I think this would be a great place, but not an option for me with the Roe SC set up.
I found a bolt to fit that above mentioned hole, but I did have to file the sensor out by hand a little to get the bolt to pass through it... and luckily it still worked, (I was glad my experiment didn't cost me a new sensor!).
Calibration was easy, the instructions said drive it at 3/4 power until the first LED just lights (small dial to adjust with screw driver for sensitivity) I just kept turning it up from min sensitivity until first led (of 5 warning ones) lit. Did this with out SC on, but as long as your sure it isn't pinging (use high octane gas for safety) you can set it with the SC on. Best wishes with it.