Oversize tire fitment

The tires you have now are the wrong ones if they are 15" That truck should have 255/70-16 on it from the factory. Upsizing to P255/70R16 on stock 16" rims will work and give you a 31.5 tire without a lot of problems or rubbing. Anything larger will rub and hit on a stock truck. Plus as you go larger you run into issues with the speedometer, ABS and gearing stress that it creates.

Thanks Steve, actually the late model XLT's came stock with 15" with option of 16", 15s are on my manufacturer door tag, 235/75r15. The Sport I think came with 16" standard. I'd have to agree with you, I don't think I want to go to big with the tires and stress the vehicle. I'm currently looking to get as close to a 16" 255/70r16, (translates to 30.06 x 10.4) as possible or your saying 31.5 or something close should translate to the 15" rim without scrub? Currently the speed is actually showing higher than the speedometer shows by about 4 mph so not worried about that, I can have it calibrated. Thanks!

Hmm, My tire distributor doesn't show the 15" rims, only a 16 on the XLT 4X4. Not a big deal though, as the chassis is the same going to a 31.5 tire shouldn't be an issue as it fits with the 16" rim. The 255/70-16 was an OEM tire size as well so those would be a bolt on and should be in the tire calibration chart in the vehicle already as an option.

Thank you Steve!