our 1978 has no roof air as we do not always need air and to save money we bought a 5000 btu wall air conditioner for a little over 100 dollars. we put ours in the front cab window we made a table to fit on over the window sill, made a panel of lexan to cover the window, slip it on and velcro to the door. works great for 125 dollars. we take it out and store in the back to move. i was wondering if anyone else had tried this? i love this group thanks i do not have much computor experience. Thanks for your patience