Looking at the roller lifter from Hughes the needles can't come out of the lifter assembly if for some reason they fail. The roller and needles are up inside the body. I'm guessing there would be a very bad noise if one or all the needles gave out. Enough to give me a heads up that there is a problem. I don't think the cam would survive a failure of this nature however if the roller seized up. Geez.... lets don't talk about it.....lol
I'll just keep running high zinc and call it good.
AJ.... your inbox is full. I can't ask you a stupid question...lol