Been there and done that on my 76 CJ5 with a 13 foot kayak and a 17 foot canoe. CJ5,s are great but they are also short and somewhat high which means when you put a long object on the roof it can act like a sail in a crosswind. I had a couple of scary high speed {60mph} wobbles with them on the roof. The rack was homemade and fastened in 6 points, the front bumper, the rear bumper and the mirror mounts which were necessary to keep the rack stable. Solution - build or buy a trailer. Mine is short and has 35 bfg mud terrains and it feels much safer carting around my canoe and kayak.