If i have an 08 screw with 18s could i down size to a 17 inch wheel with no problems. like not having to mess with the breaks and all that stuff.

 

I think if you go with the right backspace and width of both the rims and tires, you should be fine. About the only thing I can think of you'll have to deal with is the TPMS. You didn't mention the size of rims and tires you're looking for so there's some fudgefactor here.

 

i was lookin at the moto metal chrome 951s. It has a 2.5 inch autospring up front and stock blocks out back and i was lookin at runnin a 33 12.50 or 35 12.50 cooper ST. I think the 17 inch 951s have a -12 offset and a 4.5 inch backspacing.

 

You will have no problems with going from 18" to 17" wheels... Ford used 17" wheels on many of it's '04 through '08 trucks... There are some benefits to 17" wheels, higher load capacity and greater tow ability to name just two... I have an '07 with 17x8.5" wheels...



It's not an issue...

 

alright sweet!! that will save a good bit of money when it comes to buyin the tires and wheels. its ridiculous how much one size in a rim changes the cost so much for tires and wheels