727 slipping in reverse when hot

Thank you for response, I gave the car away a week ago for some registration paperwork to be done and once I get it back , I will dig into the transmission. My 1st idea is valve body swap. This will narrow things down. In the mean time I had time to play with IFR on my tunnel ram carbs so its all time well spent anyways! Will keep you posed for sure about this, I always try to finish thes threads so person with similar problem has a ready solution. The worst thing on forums is threads that dont show final solution to reported problem!