OK, I measured my piston crown to block height last night. It was protruding by .59mm, and the WRC gasket measured 1.25mm. I measured the gasket by the little brass rivets, but I’m sure the actual gasket when installed will compress a little further. So if the gasket does compress to 1.15mm as per PJ-Msports post above, that will leave me with a clearance of 1.15mm - .59mm = .56mm from the piston crown to bottom of the head.

Cheers
John