Yes, eyes always on the entire frame. They may say rust and rot free but you should always check. Make sure if anything was repaired on the frame or anywhere on the body it was done correctly and not a hack job. Make sure to check the tub well. Definitely crawl under it and take a look at the axles and tranny. A lot of times people with go off roading and crack something without knowing about it. Think about it this way, everything you find that needs repairs is just one more thing to get a discount for. Check to make sure all the lights and switches work. It really depends on what you want from this project but the closer you can get to done with your budget is obviously best. Also check all rubber seals which are probably all shot. MAKE SURE to check around the windshield frame for rust. Bad seal means rust and another windshield frame. Luckily parts are cheap for the cj. Also knock on all the body panels to check for previous bondo work. you don't want a bad bondo job, oh and the inside of the fenders where it meets the tub.