Thanks guys! Got that booger off tonight. I first tried cracking it since I'd cut a slit 90% through it already, but it still didn't get it. What worked was opening the CL442s and loosely putting the jaws around the base of the rotor, then prying up on the handles. Three good "heave ho's" and the thing popped off! Since I already had the anti-seize out from doing the plugs, I put some of that on the shaft before the rotor. Got the new cap on, and fired her up make sure the firing order and everything was correct. She was still doing the slight up & down on idle for about 20 secs, then she stabilized nicely. It's running as smooth as a brand new truck now.
Tomorrow or Friday, I'll drop in a new PCV valve, put the breather back on, and hopefully wash down the engine before I call it a wrap.
Thanks for all the suggestions guys!