I run staggered on my car and the only issue I have is if I ever got into a predicament where the larger 275 in the rear needs to be swapped to the front you cannot. I my case I also have custom offset wheels too. Right now I run 245/45/17 front and 275/40/17 in the rear.
I drive the car on the street roughly 10,000 miles a year and if I ever get a flat I am screwd
91' Mustang GT
Motor: DSS pro bullit w/0* balance and pro lite pistons, TFS heads w/ port,valve,spring work, Edelbrock air gap intake manifold, 650 speed demon carb.
Chassis: REAR, MM panhard bar, MM lower control arms, H&R springs, stock sway bar. Kenny brown subframe connectors + Jacking rails + Xtreme Matrix brace, Torque box reinformant plates.
Front: Ground Pounder K-member, Ground Pownder A-Arms, coil overs with H&R springs, MM caster camber plates, MM strut tower bar.
Also many more modifications to list.