Modifying the head of an M42

[Onz]

Does anyone have a link to or know of anywhere the cam / crank cycle timing can be found for the m42?

I am in the process of a top end rebuild and want to know the intake and combustion volumes and the standard cam timing.

Planning around upgrading the intake valves and cam duration but I want to know my starting point first.

My plan is to go 2mm bigger on the inlet valves with a higher lift and wider duration but I want to calculate the standard volumes and airflow first.