I am looking for wider tires for my '05 lariat 4X4 with factory 18" wheels I don't want to have to mod the wheel well I just want them a little wider than the OEM BFG's on it.

 

You wont be able to go much wider since the OEM wheels are only 7.5" wide (i think). You might try a 35x12.5 18 BFG Mud Terrain with a level kit if youre looking to beef your truck up some. You could also try a 33" tire. If you really want a wider tire then you're prob gonna have to get aftermarket wheels.
just my 2 cents worth

 

The 285/65-18 (33x11.50) BFG's would be perfect.