The other issue which can affect some of the A-Series heads is brass plug recession.
There are about 5 brass plugs fitted into some of the A-Series heads, and the centre one overlaps the gasket ring for cylinders 2 and 3 on the 940 head. These can sometimes shift, and effectively create a recess which may allow leakage and gasket failure.
If you have these brass plugs fitted worth checking they have not moved any time you take the cylinder head off.