The best I can offer without getting some measurements from you is to suggest that you go through this thread.
I'm going with 25x8x12 tires on 12x6 RZR LE wheels all around, I've learned from my past RZRs that usually oversized tires and wheels not only rob HP but handle worse!! Most people think they need monster truck tires and don't even use all of the traction available from the stock tires!! (unless your mudding or doing some extreme terrain all of the time) Must be a visual thing, I don't get it. All of the GNCC and off road racers have known this for years.
What is the width of the tires you want to go with?? How wide the tires are will be the problem if they rub or not. The 28" is the height of the tires which shouldn't be a problem.I also have an ACE and I am looking at buying some aftermarket rims and I cannot seem to get any specs for this thing. I am looking at buying a set of ITP SS212 (12x7) rims with a 4+3 back space and 28" Silverback Mudders. Polaris told me the largest tire I can get is 26" what is your take on this? I am probably crazy for wanting to put these things on my ACE but I am asking you all because I honestly know nothing about this stuff.