Guess someone thought that the receiver hitch was enough.
As far as locating one. Dude, I live in California.
However Jenn and Jeremiah King may very well have one but shipping could be expensive to NC.
www.kingstrucks.com
They are members here on the board
jeremiah king
http://67-72chevytrucks.com/vboard/member.php?u=41714
Might be best to find a local cut off frame section and someone to huck fasten the crossmember into your truck.