Rear Wheel Clearance Calculator
Enter your rim size and options you want to try. The diagram will change, showing you how close you would be to hitting something. Shown with stock Dana 44 axle

Wheel Size in. X in.
Offset mm
Fender
Wheel Tub
Leaf Springs
   
Backspacing:
Distance Until Hitting Fender:

NOTE: This diagram is close to exact but NOT perfect.

Other things like damaged fenders, crooked beds, different suspension setups etc. can affect how your wheels will fit.

Use this as a guide to see if you would need wider fenders, springs moved under the frame, wheel tubs etc.

The blue and red is the RIM ONLY, note that your tire might stick out past the rim depending on the size, and will of course take up room above and below the rim