33's w a RR lift? That's pretty good. Did you remove the fender liners?

Just use caution running with that much pressure. I aired up my 265's when I had them to 35 psi and found the XK to be skiddish over bumps - especially bumps on curves. 30 seemed to be the sweet spot. On my 285's I am running 35 and it seems to be civil on the street.