Adjusting valves and changing SLS fluid for free time.

Don't forget the cooling system pressure test. Pinch the upper radiator hose when the engine has sat overnight. It shouldn't feel like there is residual pressure in the cooling system. Residual pressure could mean head cracks.

A typical PPI might not reveal the early stages of head cracks and I doubt there will be enough time for the engine to cool completely while the car is at the shop.

Having the head replaced is about $2500. It might not be a deal killer.

Sixto
87 300D