I am running the diablo performance tune on a 2001 mustang gt. i believe its for 91 or 93 octane, (the factory settings on the diablo tune

What should I do to allow my car to correctly run 87 octane with the diablo tune? thanks

ok heres the car info:
99GT w/ 2001 saleen 2v na motor
75mm bbk TB and Plenum
Off road X-pipe
Borla Exhaust
3.73 gears
Factory Saleen Underive Pullies
Vortech S-Trim V2 non intercooled 8 lbs of boost

ok now my question:
The supercharger was just put on and I am running the performance tune, will ...