I've got 245 front 275 rear with 8.5's all the way around. I've had no problems except mounting the darn things, that's the hardest part. Once you set the bead and apply the pressure it's pretty difficult to cause any problems. Also, I use the stock 17's for racing/auto-xing and I've got 255's up front and 275's on the rear, so if I can slap a 275 on an 8 inch and race, then you will have no problem "streeting" a 275 on the 8.5

 

Thanks Bailey! Just one more question, why are your wheels different?

Looks like I'll get the 275/40 18's then! Thanks all! Now I just need to decide on the make, probably getting the O.E. Mich. Pilot Sports since they match the front.