[Dick M]

I would not use a rag to jamb the gears. Use some slats of wood about 4 or 5 inches long. Place them on both sides of the cam gear and clamp tightly with 2 'C' clamps. Both pieces of wood will lodge against the pan/block when you begin to turn the cam nut loose. Use the same method when installing the new cam gear. I have a good impact wrench and used 100 psi of air. The impact wrench struggled a bit at first, however, after some banging on the nut, it came loose...
One thing to know: If you place the cam nut wrench all the way onto the impact wrench stud, the cam nut wrench will not seat on to the cam nut. Place the cam nut wrench onto the cam nut. Then, put the nose of the impact wrench into the cam nut wrench as far as it will go. It will hold and hopefully break it loose.