What will you be putting on the back of your 72? Reason I ask is that the Avon to be replaced is currently on the back of a 56 Manhattan and will soon(ish) be on the back of a 70 Manhattan, so similar to your available space (I am guessing).
Does the Williams sink at the stern because it's less flat? You're by all (including yours!) accounts a tall man. Would a mere 6 footer fare any better?
My friend is all for a 4-stroke Avon. I'm happy to quash any thoughts of a Williams if that's the advice. Wish I knew more.
Thanks again!
-------------------- "You live longer once you realize that any time spent being unhappy is wasted" - Ruth E. Renkl