[dtw]

This could be something as simple as a couple stuck chunks of carbon. Not probable, but possible.

The labor prices aren't way out of line. The parts are. Can't imagine all valves need replacing, and there's no need for the ARP hardware and titanium springs unless you are building a race engine.

You don't mention what kind of engine this is, what the maintenance history is, or what the mileage on it is, to give us some context for your current compression and leakdown figures.

Need in-put!