Ive got the knocking sound which seems to be coming more so from the passenger side. It popped up when I was on the highway the other night, and made the audible knock sensor go crazy. It was too much for me to drive it. I wound up towing it back home. Do you have a oil pressure gauge? How does the oil pressure look? Mine never dropped off and looks good at all rpm ranges.
I took out all my lifters and I could not compress them at all. I took one apart and drained the bit of oil that was in it and was then able to compress it. I dont know why it was trapped in there causing it to seize up like that. I didnt want to go through all of them doing that and still be paranoid that I was risking something so I just put all new ones in. I got it all back together and of course, it still knocks

. Other than lifters, pushrods or the rockers, I dont see what could be the problem. It sounds horrible, especially when I rev it. The sound gets louder and more irratic. The car was running great with no problems for a couple thousand miles since doing cam,lifters,valve springs,heads,etc.etc. Only tap/knock I recall before would only last for a few seconds, and would occur when starting the car after it had been sitting overnight.
I remember reading about cracked rocker shafts. Also, broken inner valve springs. I will check these out today.
Good luck, I was just wondering how your situation was going since it sounded alot like mine.