Just some quick math would say your 160 pounds is offsetting the keels lever arm somewhere around 20 feet off the water. Above that you're relying on the form stability of the hull, so 'yes', all the way up the rig should get real squirrelly! That presumes the center of the 1100 pound ballast is about 3 feet under water (3300 ft lb of potential leverage). I know it's a LOT more complex than a seesaw, but at the top of the rig your lever for that 160 pounds is probably around 28 feet above the water (over 4400 pounds).

:: I went up the Express 27 mast not long ago and had a
:: somewhat scary experience.
::
:: I weigh 160, and at the time there was a 200 lbs guy on
:: deck with the boat tied to the dock. I was at the top of
:: the mast doing some work and the guy on deck stepped to
:: the rail to do something. The boat started heeling
:: pretty extremely and truly felt like it was going to to
:: roll all the way over until guy on deck jumped to the
:: other rail to stabilize the boat.
::
:: Would the boat really roll over like it felt it might?
:: Any experience with sending people up the mast on this
:: boat and how much weight is too much?
::
:: We plan to go up the mast fairly frequently with the new
:: offshore rules for mounting and removing the masthead
:: VHF when doing offshore races, not to mention if we ever
:: had a problem and needed to ascend the mast while on the
:: water.
::
:: I'm wondering what is safe?
::

:: -dan