I'm confused. I'd like to put custom wheels on my toy but not sure how to measure for them. What will fit under the fenders and not rub the inner fenderwells as well? I'd like to go 315 on the rear and maybe 275 fronts. What kind of offsets would I need or would I have to use spacers?

 

Not sure if anyone on the forums has done that same thing. Tire shops would be a great help, starting with the rims then tires. I think they could match you up!

 

Check with Tire Rack online. They might have the information you're looking for.
I have seen on TV equipment that can map the entire inner wheel well and body with respect to the hub. Then they can take that information and determine the size wheel, offset, and tire size that will fit. Not sure how you would go about finding a shop that could do that.

 

Maybe check this out: Rim & Tire Size Calculator. Custom Offsets - Wheel-Size.com
I think if you do a little measuring and research, you'll find your answer.
Good luck.