Are you taling about 275/60's or 275/50's? In either case, that tire is too wide to mount on the front. The 275/60 is also too tall for the front. Both will rub around turns. They will also look ridiculous on front too.
For the front, most go with 235/60's on the factory rim. This is the same height as stock, but a little wider for better handling.
On the rear, you can do either on the factory rim. I think the 275/60's are too tall, so I have 275/50's on my factory rears. The 275/50's are also very close to factory height, so it wont throw off your speedometer. This tire is a little wide for factory rims, but mine look very cool and are wearing fine. I also didn't even need spacers! Those rear tires are a HUGE improvemnet over the factory ones!
