Death of a lifter or lifters?

I assume i have a lifter that has collapsed, i have narrowed it down to that or to a rocker arm. My entire valvetrain is rackety (if that is even a word) here lately. I have replaced the oil pump, the pickup and changed oil a couple of times. I am curious as to what will cause a lifter to go bad.... low oil, over revving, i know one thing, the motor has a lot better oil pressure than it did before now, coild the oil pump have been on its way out and cause a lifter to go bad.....i could make a video so you guys could here the sound i guess.

I should note that i have check the valvetrain to make sure it has the correct geometry. Everything looks fine there.


anything else i can check for?



thanks for help
jason