i wrote out a nice reply and thats when the forum glitched again or something, i got pissy and didn't type it again.
i haven't heard of stroking the 4.2, the 4.0 engine uses the 4.2 crank to make the stroker. so putting the stroker in a 4.2 jeep is possible, but it means using all the engine management (fuel injection and so on) from a 4.0
i suppose you can use a 4.0 w/ 4.2 crank and use the 4.2 head and all, but its not the same as the traditional stroker, plus the carb would probably have to be changed, or swap to fuel injection, and by that time i'd rather use a traditional stroker.
so putting a stroker in a 4.0 jeep is almost as simple as a rebuild, but putting it into a 4.2 jeep is not.