Yeah, this thing's got me on tenderhooks as well. I'm checking every two hours, or so, for new developments and would love to hear for myself what that sound really is like. Alas, I'm too far away.

Jeff,
The more I read, the more I'm beginning to think that what you're hearing is not coming from the camshaft or its accoutrements. I wouldn't want to bet on it, but I'd look elsewhere. An exhaust manifold leak can sound much like a knock, and then there are U-joints, driveshaft carriers, loose bellhousing and tranny-to- bellhousing bolts, contact between exhaust system and body. Who knows! I'm as mystified as you but, of course, you're having all the fun ;-) Maybe you meItioned and I didn't catch it: I'm assuming the speed of the knocks correlates with engine rather than wheel revolutions. I'm sure you'll get to the bottom of this eventually and like you, i'm sure, I hope that will be soon.
Bob S.