That's good info on the supercharger, I will definitely pass that on to the tuner. What kind of boost levels were these other guys pushing? That has a lot to do with knock, so does the fuel octane and intercooler efficiency.
The intercoolers are horrible on that thing. Stock boost was 8 psi on a 6.1 so unless they pullied it for the 426 it should only make 4-5 psi. There is a quiet drive upgrade for the supercharger if you can find anyone from Techo to install it.
IAT's were through the roof on those blowers too. Figure about 245-300 degree's under full boost which is really bad for these motors. Use a larger heat exchanger then the one that comes with the kit and you can bring that number down. Also they had water pump failures for the intercooler. it's a 2003 mustang pump that can be purchased at any parts store. If your guy needs more info he can call me.