I have a 2015 F150 Crewcab with 5.0. It has stock suspension but I removed the rear lift blocks. I want to put 33x12.5x20 tires with aftermarket wheels on. My question is what offset on the wheels do I need for that size tire to fit? Also if I have to trim any plastic, what and where will I need to trim? Thanks to anyone who can help!!!

 

You can run a lot of offset if you don't mind the tires hanging outside the truck's fenders. If you want the tires to be flush with the side of the truck then you might have to trim the crash bar in the front (not recommended). If you can use your stock rims than a small hub spacer might do the trick http://www.wheeladapter.com/

Need more information to give best advice

 

The greater the offset, the more load and wear on the wheel bearings and suspension, good point is it keeps mechanics employed.