I have noticed that ever since I put larger tires on the truck had been wandering almost like you are hit with a gusty of wind here and there on the highway. Original tires were 245 75 16 then I went with 265 75 16 and my last tires I bought were some 285 75 16 Michelin LTX AT. I'm running tire pressures of 35psi.

 

Also on a side note my front end is all right no movement in nothing, maybe should I increase the tire pressure?

 

What tires did you get? Some tread patterns are more prone to follow imperfections in the road....... ANY slop in your steering will also be amplified by the bigger tires, and it isn't just the steering either. Anything in the suspension that has a joint, or bushing, is a possible contributor to the problem.

 

How wide are your wheels? A 245/75R16 tire requires a 6.5-8" wide wheel, while a 285/75R16 tire requires a 7.5-9" wide wheel. If the wheel is too narrow for the tire, it causes the sidewalls to bow in and can cause the tires to walk down the road funny. Wider tires are also more prone to wander around the dishing that forms in all roadways. I generally won't run anything wider than 265 on a street vehicle because of this.