Valve Depth ?

[PANCHORFO]

Hello there,
I'm Doing HGs on Friend's LLY, Using ARP studs and Grade C gaskets.
I was doing my homework and checking the Intake and Exhaust valve depth on the head.
Intake Valve depth : 0.5 mm
Exhaust Valve depth : 0.8 mm

I read somewhere that the factory valve intake/exhaust depression is 0.6 and 0.9 mm

Meaning that the Machine Shop machined 0.0039'' ( but they told me that were machined down 0.0056'' )

Am I missing something ?

 

[PANCHORFO]

Intake Valve depth : 0.5 mm ( 0.019685'' )
Exhaust Valve depth : 0.8 mm (0.0314961'' )

The intake valve depression is 0.6 mm (0.0236 in) and the service limit is 2.5 mm (0.0984 in). The exhaust valve depression is 0.9 mm (0.0354 in) and the service limit is 2.0 mm (0.0787 in).