Gave up on the research, got time this weekend to attack the Freeze plug. Pulled the old one out, it is 40mm and a b!tc# <img src="/forums/images/graemlins/scared.gif" alt="" /> to get new one in. Even with the alternator out there is only a couple of inches to swing the hammer.
Next on the list is the leak in the radiator. Have to find exactly were it is leaking to see if I can repair it or shell out $200 for replacement.

On a happier note my new snorkel has finally arrived and once I have the water issues out of the road, I will start fitting it. I will put up a new post on how it turns out. <img src="/forums/images/graemlins/kewl.gif" alt="" />