Will a 255/50/R16 tire fit on stock suspension?

[Doober]

I'm pretty sure it will... with the right backspacing. I fit a 275/40/17 in the rear, only slight rubbing on the wheel well lip without any rolling/trimming. A 255/50 would likely fit up front going straight, but might rub in a turn.

 

[Doober]

Did you measure backspacing? About 5.875" will be your absolute maximum for clearance at full lock.