front and rear track
If the car had wider rear tires than fronts, and the outside/outside measurements were the same, the "track" at the centerlines would be slightly smaller in the rear.
Jon
Your concern seems to be where the outside edge of the tire is. My advice is to mount the body on the chassis before you decide on tire size, wheel width and offset. There are some neat measuring fixtures you can buy, or even build yourself which let you mock up any tire size on any wheel diameter and rim width and offset.
If you plan to drive the vehicle, you should check clearances to the body, fender, frame, linkages, etc. thru at least some of the bump and rebound travel with the front wheels turned left and right and all of the bump/rebound travel with the wheels straight ahead. With a solid axle rear you should also check with the axle rolled at least a few degrees and thru full travel with no roll.
More than you probably wanted to know.....
Jon

