Rudder post stuffing box question

[z28jimi]

Purchase survey for my '06 44 DB noted a small leak at the starboard rudder post. I'm going to slither back toward it in the next week or so, and would like to go in armed with the appropriate weapons. Does anyone know what size the nuts are on this stuffing box? I have enough assorted channel-locks, pipe wrenches, chain wrenches, etc., but I'd prefer to go after it with a couple of properly sized open end wrenches. I've seen them advertised, made for this purpose...I just need to know what size to get. Any assistance or advice will be appreciated.