In this case, to simply go with a wheel that is of a larger diameter, there is no need to make any adjustments to the ride height.
325/60/20 = 35.35 x 12.8. And there is no way a 33x12.50 is going to fit on a 10 wide wheel with just leveling...even on an HD. It would require a good bit of fender modification.Tell your buddy to get a 325/60/20 which is a 33 13.50 it should work out good. Well atleast i know in cooper stt's its a 33 13.50 might be a lil smaller in other name brands. Either way a 33 12.50 he should be fine with a 2.25 inch readylift leveling kit!