Ive never been pulled over for anything goin on with my jeep. A cop saw me turn around after passing him, and pulled me over for acting suspicious, and MENTIONED that he could get me for tires, but let me go without much of a fuss.
I think in PA...when they say the 3" thing, that means the FLARE cant extend more than 3" past the body lines. Also...sometimes the state cops will take a penny and place it against your flare and let it drop straight down. If it hits your tire...they got you...if they are being that strict.
The bumper height and tire thing screwed Lee awhile back. He tried to register it as a truck...which they wouldnt let him do. There are guidelines to what you can register as. It might depend on the place you go to try to change it...Im not sure. But....the XJ is technically listed as a station wagon. You CAN get them to list it as a MPV (multi-purpose vehicle). That will give you some wiggle room with your bumper height. But again, that might depend on where you go, and you'll end up arguing with a cop about it most likely.
I really got into the technical specs about the laws when Lee had trouble, and there really are some detailed things in the books. Like not being able to extend your bumper down...they measure bumper height from the mounts etc etc.
For what its worth, we put rear rubicon flares on the front of Lee's jeep, and they covered 33"x 12.5 tires on Crager soft 8's perfectly.
here's the thread.
http://www.naxja.org/forum/showthread.php?t=920713
It looks to me like regular TJ rear flares will be enough to cover the back tires...never got around to installing those.
Its a bummer to try to modify anything in PA...cars trucks or jeeps. Only gonna get worse.
J.