Second generation Escorts are all similar to the Mazda Protoge, but they are not the same. The GT is most like the protoge, but even the LX & pony are similar in some ways and not in others. It isn't the same from year to year, so there is no way to have "facts straight" with such a blanket timeframe of 91-96. However, to answer the original question, you CAN put a Mazda engine into your LX because the GT is a LX with a Mazda engine basically. Yes there are a lot of other things that are different, and you would be required to change some, but not all of them to put a Mazda engine into your car. Puttting a Mitsubishi or some other manufacturer's engine into your car isn't worth it, and would be pretty much impossible for you to do yourself anyway. You may want to look at just replacing the part that "broke inside the engine" as opposed to putting a whole new engine in the car. You could get a new Ford engine for the car, that is newer than the one in there, and not broken, but the same basic engine, but even though it has hints of Mazda involvement (or rather Ford mimicing Mazda's protoge and 323 designs) it IS a FORD engine NOT A MAZDA or MAZDA REDESIGN. It will not be as reliable as the Mazda engine, and will take FORD parts... so decide what is best for you, and stop wearing that nasty thong.