[C320-list] Sterngland adjustment question

[Graeme Clark]

Looking at the manual one part says that the stern gland stuffing box should be adjusted to 1 to 2 drops per minute (engine off)  and another part says 4 to 15 drops per minute, which seems rather a lot - anyone care to give some advice?  

Secondly we have in the past had a contractor do this adjustment because we don't have any wrenches big enough.  This is getting repetitive and expensive so I want o buy some wrenches but have no idea of the size of the nuts (I'm currently 450 miles from the boat!). Does anyone her know the correct size? 

I watched one contractor and he tested/measured the water loss rate only when the engine and props haft were turning, but not user what would be an appropriate rate in that case?

Thanks in anticipation of the answers!

Graeme
#303, England.