That confirms a couple things I found on the web. Unfortunately it looks like doing this on a boxer engine is much much more time intensive than doing the same job on my carburated LS1. And it will take some time before I can complete this repair.
We aren't experiencing any misfires or power issues. is this something that we can do limited driving on until we get an opportunity to fix it? Or, could this cause catastrophic failure. I can't think how it could but my valves tend to tap from being under lubricated, not over.