Earl Ford,
I just went through doing what you are trying to do. I have a CC 46 inch deck and I put it on my 682. I have a spare hanger so I started cutting one of them to make the deck work. The first problem was the crossbar at the rear so I took my 4 1/2 grinder and cut the welds so I could make a trial fit.
The next problem was the belt track from the mule pulleys to the rear pulley. I could sight back from the mule drive and could see that the belt needed to go right through where the 2 arms are that slide into the slotted hangers at the front of the deck (the arms on the upper part of the hanger..the part that has the picklefork). I tried to get some pictures of this but they did not turn out and I was in a hurry to get at fixing it. I also tried to locate a hanger from a CC cub but no luck so I look at one on a local 1540 and decided I would stick with the IH hanger because it was so much beefier.
My previous deck was a 50C and it tended to wear the belt by rubbing on the left-side hanger so I had always run that deck with the left slotted hanger removed. In this case the arm that engages the the left hanger and it's brace was also in the way so I cut the entire left hand arm and brace away. This pic shows where:
I also unbolted the left-side slotted hanger fitting from the deck itself. So when the hanger was back together the only arm that goes into the slotted fitting in the deck is the right one and the entire area in between the mule pulleys and the rear drive pulley on the deck was absolutely clear. I call this stuff the straight-shot hanger mod.
I made a trial pass at the lawn and found that the rear spring-loaded attachment pins tended to drop out. So I took the pin assemblies out and ran 1/2 inch bolts with self-locking nuts through the attachment holes to let me continue testing. Next I found the deck drive pulley was riding too close to the left-hand hanger and was rubbing on the hanger so I simply moved the arms over on the other side of the brackets on the deck. This afternoon I mowed my entire yard (about 1/2 acre) and am convinced this deck is so much better than the 50C by such a large amount that I will never go back.
I intend to keep making changes like welding the rear cross-brace back on so the it clears the pulley from behind, to make some bends in the left-side arm so I can restore the spring pins to use, and to restore the left slotted hanger to use by moving it out of the way with an adapter plate.
I hope to get some pictures when I have more time to put more work into it. Maybe this will make more sense then.
JimE