I also run 20x11's in the rear. I agree with Kona, if i had to do it again I'd probably go with a square setup, or 20x10 in the rear. Largest you can fit up front is a 20x9 according to those I've spoken with, so you're stuck with a 275 max up front. As far as the rear goes, 295 and up only, and 295 is a stretch on an 11" rim. You'll find yourself severely limited on tire choices for the rear. 305/30 or 315/35 is about it, and depending on your drop, you may not can find front and rear tire combos to fill the wheel well gaps you're after. I'm on Steeda ultralite springs, and the 315/35/20 in the rear is just too much, I get crazy rubbing on the splash guards.
Once my Nitto INVO's are done for, I'm gonna suck it up and spend the bigger bucks on some Michelin pilot super sports I think.
265/35/20 27.0" diameter front
305/30/20 27.2" diameter rear
27.0 is the original diameter of the 19" 255/40/19 brembo tires. There's just not a whole lot inbetween 27" and 28"+ on 20's, at least not when trying to keep the front and rear diameters somewhat similar. 315/30 is the perfect rear size IMO, but the only company that makes them is Toyo and their R888's. I daily drive my car, so I need something that's gonna give better mileage and wet performance.
Black 2013 GT Premium | Track Package | Recaros | GT500's | JBA H-Pipe | Borla Over-Axles | OEM GT500 Spoiler | Koni Yellows | Steeda CAI/Tune | Steeda Ultralite Springs | Steeda Adjustable UCA/PHB | Steeda Billet LCAs | MGW | Forgestar F14's