[Doc]

Considering the amount of power you've put in that car, I honestly would say in all good conscience you should not use that tire/rim combo. Putting a tire designed for an 11" rim on a rim 2" smaller is just not a safe thing to do IMHO. The sidewalls are designed to handle the weight and stress according to the support from the proper rim width underneath them. I think you're just asking for sidewall failure or a blowout of some sort. I'd hate to see you get hurt or damage your beautiful car.

The factory 275 is the widest tire safely recommended for a 9" rim, and it's actually designed for a 9.5" rim ideally.