Our Hunter 336 lists to the starboard. Cant find the reason why. Could there be a weight distribution difference with storage, or tanks?
is the boat empty and cleared out of all gear, personal items, tools and extra rigging such as sails, line and anchors?
when the boat is empty, how does it set in the water?.... if its trim, then load it accordingly to keep it trim.
if the boat is not trim, then you can either do like Stu suggested and add some useful permanent ballast, or just load all the stuff that you want back on board so that the boat becomes trim as it takes on weight....
the tanks (fuel, sanitation, freshwater), whether full or empty at approx 7.5-8lbs per gallon will absolutely affect trim and there is nothing you can do about it except adjust the gear around in the boat as you empty one tank and fill another.... and depending on where you sail and the sea conditions this could be a necessity, but it may be bit extreme for the average day sailing....