Here you go bro. It's explained in the link below but try and use google before asking questions. That's what I do! lol Link: http://www.tirerack.com/wheels/tech/techpage.jsp?techid=101
And with our trucks too much positive offset will hit the strut rod. And too little positive offset, or having negative offset, will touch the outside of the fenders. You have to think about turning the wheel and where it will touch. You should be a able to measure and get a good idea. It is harder to get wheels to fit up front especially if they are wider. I went with 8 inch wide +35 offset. If you are lowering your truck you will probably need to tub the inner fenders and firewall.
off set is measured in positive or negative millimeters. Most wheels will be found positive. The more positive an offset is, the hub of the wheel is pushed towards the outside. The more negative an offset is, the hub of the wheel is pushed towards the inside. Neutral is right in the middle. Positive brings the wheel closer to the truck. Negative brings the wheel away from the truck. Low and High means how MUCH of a positive OR negative offset you have. Generally most wheels will be referred to as a High or Low Positive Offset. You will rarely find negative offset wheels.
