Holy Crap!! I just found the Massachusetts Registry regulation for lifted vehicled (540 CMR 6.00 Alteration Of Motor Vehicle Height), and the formula used is as follows:
(wheelbase x track)/2200=max allowable mechanical lift
The lift can be all suspension, all tire, or any combo. The 2200 value is the "Safety Factor". No idea how they come up with that.....
Using this formula, I can only lift my XJ a max of 2.67 inches!!!! The actual measurement from the bottom of the door edge to the ground allows a fudge factor of 1 inch to allow for production tolerances.
I hate this state more every day.......