its a puzzle i had new lifters in mine i broke all the rules and ran old lifters in the wrong holes
no cam wipe, but clacky continued in its random and annoying way.
i adjusted the rocker height
swapped rockers and mounts (ball studs on mine, got studs seperate balls and posi locks)
checked pushrods
i could see no physical issue with clearances in the bore.....
i had the lifters in bits
i too had no idea which way to put the metering plate back in due to variance between sets
i was genuinely baffled and gave up...
i could have shimmed the spring in my pump to peg the oil pressure to max, but id ruin my pump and cam....
hence my only guess something to do with the oil or
My oil was foaming maybe foamy oil won;t pump up a lifter but you would expect low pressure issues all over the place.
i'm sure there is a simple reason i could not find it
Dave