According to Autotrader.com, a 92 MJ 2WD Auto weighs about 3100lbs. A similarly equipped XJ of the same year was about 2900-3000lbs. Although one might assume the MJ to weigh lees due to less physical body, the "truck" parts put in(don't ask me what) make it tip the scales a lil more. For speed, an XJ will be more favorable weight wise and aerodynamically. Also, they are a hundred times easier to find and will end up cheaper. Good Luck!