Years ago, when I first started visiting the old ITOG board, there was a very strong bias toward the 2.6, but that was before any of us had done the 3.4 conversion.

Truth be told, there is very little difference in the two powerplants in terms of criteria that you stated, i.e.,



The HP and torque numbers are pretty close. Any other criteria that favors one can be offset by a criteria that favors the other.

At this point, assuming that you are going to leave the engine stock, it will come down to the condition of the particular vehicle that you find. I would look for the cleanest, lowest mileage, best-conditioned Trooper that you can find, period.