It didn't take long to see why the puck was leaking so badly when I got the valve cover off..the cam tower bolts were loose. Not loose like I'd forgot to tighten them, but I could rock the very top ones back and forth. I took out the correct torque wrench and found that they were stripped. Further investigation uncovered a few more that wouldn't torque properly. So, I tore the cam and towers out and installed helicoils in all twelve cam bolt and stud holes. I had to be very meticulous about prep and clean up with the drilling and metal shavings. All told it took about three hours, but I'm confident I've fixed the cause of the leak now, and I'm going to re-torque the head, put it back together and put some miles on it without going further for the re-bore. If it ends up needing it, I'll do it.