Honestly Matt when you are talking about a 70's CJ there could possibly be just about everything under the sun wrong with it. I'd check around all of the major places where rust can start. Windshield frame, rear quarters, rockers, frame etc..... Test drive is going to be pretty important on it also. Make sure you put it in 4wd and make sure to lock/unlock the hubs to make sure everything is functioning properly. Everything is pretty simple on a CJ.