There are alloy and cast iron heads in both 66mm (A7) and 70mm (A10) chamber sizes, fitment to suit engine type.
On an example to hand* measurement from head gasket face to rocker box face is 70.6mm. Measured from worktop surface to rocker box lug with cheap digital sliding caliper. As common parts were used across the range this is a reasonable start.
Swarfy.
*Early A10 iron head narrow fin type. Casting number 67 251
