sorry to rain on your parade, but yes, a SOA is illegal in massachusetts. as a matter of fact, ANY alteration to vehicle height is now illegal in taxachusetts. yes, that's right, this state $ucks. according to the new enhanced safety and emmisions inspection, that was introduced last october, there can be no more altering a vehicle's height. they wont specifically look to make sure you didnt convert to SOA, but they WILL measure the height. I have a 3" suspension lift, a 1" body, and 33" tires, and when I pulled into the inspection place, the guy's first words were "how high?" and i said "huh?" and he told me that you cannot alter the vehicle's height anymore in MA. he showed me the regulation book.
they measure the vehicles from the bottem of the door opening. odd place, i know. why not the bumper? you got me. well, the measurement is supposed to be no more than 25" from the ground to the bottem of the door opening, with a 1" tolerance. mine measureed out at 34". there is no way that even a stock cj could pass then, i figured. so needless to say, i didnt get my sticker that day.
thats not to say you still cant do it. you could always throw on some p215's for inspection time, like i do. the 2nd place i went to didnt bother to measure me, b/c with the small tires, it appeared close to stock height. i also have to swap in my stock exhaust manifold, with a catalytic converter and muffler, so i will pass the visual inspection, even though i am exempt from the emmisions test. any vehicle that came with a cat from the factory has to have a cat to pass in MA. anything newer than '83 has to pass emissions.
so, in conclusion, i would say go for the SOA, and get a set of p215's or smaller, to swap on for inspection. and hunt around for a more leniant inspection station.
'83 CJ-7, 258, TR ignition, headers, T5/D300, 3" suspension, 1" body, Moser 1 pce axles, Model 20, 3.54:1