* Thought I would finish this thread in case anyone is waiting for the answer. The right exhaust cam skipped one tooth retarded and went unnoticed. The other three cams were spot on. Be sure to crank through a timing check AFTER reinstalling the chain tensioner.
* I reread the fine print for the misfire code P030X. It states that the misfire can be ignition, mechanical or injection. I can vouch for the fact that an exhaust cam one tooth retarded will set misfire codes on the whole bank.
* Five hours of extra work, and resetting codes and adaptations and this 420 is smooth and quiet again.