Ideas on what's causing my click/tick/rattle noise?

I agree that it sure looks like oil is getting in the chambers. When I pulled the plugs for a check at 500 miles, the threads were wet with oil on several of them and they looked like crap. I have a pic in post #121 but here's a bigger and better one. The plugs are in order 1-6 from L-R. I have the second set of plugs that ran for the last 200 miles, I'll get a pic of those later today.

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The head was redone with all new valves, guides, and seals along with porting and an oversize valve job. Is is possible that stuff could leak when it's all new? I will double check the rings and ring grooves. These also were all new, but I'll check them anyway.
What kind of valve stem seals are in the motor, umbrella or positive?
I agree that oil on the sparkplug threads is an indicator of a lot of oil getting into the cylinder. Are you seeing blue smoke out the tail pipe?