Depends on what you call "significant." Some of use have noted a drop of up to 1/2" in the cabin sole next to the mast bucket. In my case, the sole bends down around the bucket as the bucket drops a bit when the rig is tightened. Those of use with this 1/2" drop have sailed with it, without mishap. The early boats, I think, had no or little tabbing on the aft head bulkhead, which of course was a major problem. That was not true on my boat (#163) and should not be true on a 1980 model. But there may have been some repair done on mine, since the sole was cut away on each side of the bucket. Is yours? Either originally or on recall on mine, the bucket was itself glassed to the hull along its port and starboard sides. Also, there was some attempt, either at construction or thereafter, to put some resin and glass between the bottom of the bucket and the top of the ballast. Otherwise, the bottom of the bucket had nothing to press against. The whole bucket thing was a Morgan, not Brewer decision, I think. In the 383 and 4, I think, Morgan increased the layup schedule on the hull in way of the mast and let the mast sit on the encapsulated ballast. A better design. If your sole drop is more than 1/2", your surveyor should have noted it for you. But some surveyors are better than others.