Wheel dilema need some advise

[TXcharger70]

Ok so I just pulled my wheels off cause I was going to get a set of new tires since the ones I currently have were dry rotting. Come to find out I have 15x7 wheels and not 15x8 American torque trust II like I originally thought. My plan was put 275 60 on the rear and now I don't know what to do? What's the widest tire I can put on this rim 255 60 or could I still go with a 275? What would you guys do, just stick with what you got? Buy a new set of wheels? The wheel came with the car when I initially purchased the car. I looked at widening the wheels but doesn't make since cause of the cost. I was just not expecting this. I was convinced I had 15x8

[469 runner]

255/60 will fit fine on a 7" wide rim.  For a 275/60 you would want a minimum of 8" wide.