I swapped a YJ frame to my CJ the only difference I noticed was the CJ frame is hollow all around, the defrost has to heat up the entire windshield frame which has the effect of cooling the air in it, not a big deal in California but here the winters can go as low as 45 below with the wind chill. The YJ frame had a baffle welded or formed into it a little ways up on each side which meant the defroster gets a shorter path to the windshield and doesn't have to warm up the whole windshield channel. Other than that the one I got was the same dimensions etc as the CJ.