2002 f250. i put a 3.5 inch leveling kit on it. what size tires can i run? 33s? 35s?

 

You can put a 35 on their but may rub on the leaf spring (t least thats where mine did) depending on how aggressive you go, but a 33 no problem.

 

I have a 2000 f350 dually with 4:10 and im wondering if i could put a set of 33's on to off set the gearing a bit without having to buy spacers for the back

 

Debatable, some will have an issue if the tires are rubbing. Some will say the spacers are not as safe. I personally ( this is only my opinion) like the spacer for the look and the performance. If you were to run them crammed together the mud and possibly even snow would have a greater chance to form one super wide tire creating what I would think of as a problem. With the spacers the mud will have a better chance to "clean out". One issue with spacers on a dually is that the rims mount hub centric. With your typical alum spacer, there is not way to center your outer wheel. If you order the steel spacers like mine, they have a machines lip that insures a centered wheel. The end result is less vibration and even distribution between the tires. Not sure how critical it is, but I felt better about it. I have a couple videos to share on this.

 

Both of these trucks have wheel spacers. Neither clogged in this field. The blue truck has 285's and the white truck has 235's.
http://m.youtube.com/watch?v=yAJQpMYFI0k#