Pooparu

I have an '82 3 door GL 4WD with a four speed transmission, and I was wondering if anyone knows of the best model and year for the easiest swap into my little GL. Also what would some of the cons be for this kind of swap? Mainly I just want to make it easier to drive on the freeway, but I don't want to do it if I'm going to loose any low end when off roading. Thanks, Pooparu