When this day comes, it's always a shock. When my engine started to show signs of senescence, not only were the cam lobes worn beyond limits and the lifters spalling, but the crank was not serviceable either. (On its second run already) In the end, the only serviceable piece of the engine was the case! The OH at PennYan was timely and awesome. I got a high-compression STC to get a power upgrade during OH at no cost other than the STC paperwork. Ultimately, I got an engine that will likely last the lifetime of my ownership, and has fewer problems than the prior, pre-owned, used, and abused engine had. When you are done, you will know that every part started from essentially brand-new condition, and you will know how the engine is treated on a daily basis. The upgrade of my engine to slightly higher power made a huge difference in climb capability, and I took the opportunity to replace the prop with a better matched STC prop at the same time. Since your prop is also out of spec, this might be a good opportunity to install both a HC STC and a better-matched prop "while you are at it." It's certainly cheaper (like free) to do the HC STC during OH.