It was definitely over loaded.
The frame will need straightened before putting a new hitch on.
Some pics the op posted:
http://67-72chevytrucks.com/vboard/s...&postcount=923
http://67-72chevytrucks.com/vboard/s...&postcount=924
I don't want you take this the wrong way, but towing that much weight is very unsafe. It's on thing if you are towing off road or down a farm lane, but you have to remember that you aren't the only thing on the road. Other drivers are at risk if something happens to your overloaded truck.
These trucks are rated at 10,000 for the rear hitch receiver, and 12,500 for a fifth wheel. You need a bigger truck(medium duty) with a fifth wheel hitch if you arte going to continue towing that much.