In this photo I left about an inch between the male end of the stuffing box and the female nut. This is typical of the space you'll have on many production boats like the Catalina 30 & 36. If you have not attempted this type of DIY job before it's best to do it with the boat out of the water for obvious reasons. With the female flax nut removed water will flow in to the boat from between the male end of the box and the shaft!