I didn't disassemble the heads. I put my trust in IMM's quality.

I don't think it was a preload issue. The adjuster on that rocker was set no different than any of the others. That said, they all might have been too tight and that one was just first to go. Or it may have been my choice of oil.

Oil consumption was probably due to the intake lobe being wiped. There was pretty much no valve lift remaining. Without the valve opening, it was pulling a bunch of vacuum in that cylinder and sucking oil past the rings. That's one theory anyway. Similar thing happened when I lost an intake rocker on a 440 several year ago.

This cam is much quieter than I ever recall the other being. It's a very similar grind to the old one (XE274H vs XE275HL), albeit with more lift. I expected more noise if anything. Makes me wonder if there may have been an issue from day one with the old set up that I never noticed.