you cant acurately ask this question as every head will be different! you can only give a rough idea of what they could be.
You can get specific measuring fluid, its called GUNK, works a treat! as danny said, bit of grease round a perspex ring, with a hole in it, doesnt need to have two holes if you have the head on a slight angle, the air will buble out ok. dont use too much grease either,
we account for grease by subracting 0.2cc from the measure, but if your frugal you shouldnt need to subract anything
thats just for the burger fingers amongst us!