The liquid post on your Cornelius Super Champion has 19/32"-18 threads, and the "type A" post fitting you used has 5/8"-18 threads. If you tightened it down enough to get a good seal, then there's a very good chance you munged up the threads on the keg, and it will be hard to get it to seal properly in the future.
I'm trying to find some porn filmed by a dog wearing a GoPro. - SharonaZamboni
Hunter, when you get bored, will you put a taco in my elephant's hands for me? - Hat