For those of you who have done this, did you use some kind of special tool like
this ? I have a book about engine blueprinting that says you should take the compressed head gasket thickness into account when calculating the compression ratio (first photo below) but all of the formulas that I have seen for calculating an air-cooled VW's c/r (second photo) only take cylinder volume, deck clearance volume and combustion chamber volume into account and disregard the thickness of the compressed shim between the barrel and head. Is the thickness of this shim insignificant?
