Hi Dustin, 33's will be your best bet, 34's won't be bad but either will require trimming. Marlin (Chris) is running 34" tires with 919 springs. Anything over 32" on even stock rims will require trimming, shoot even 32" tires on stock wheels will require SOME trimming, especially if you plan on taking it offroad. A 12.50 tire wouldn't be very good for your x7 rims but WILL fit but will require more trimming than say a 35x10.50 and will probably rub frame a good bit, but if your not planning on going with the 919's plus spacers and alot of t-bar crank, stick with something like a 33" or a 34" tire. That's just my opinion though. You've seen my truck in person with 33x11.50's and I have 912's, you'll probably have about .5-1" more lift than me with the 919's (I think a whole inch is pushing it but we have alot of mixed opinions on this)