The 4x6 Redwood ceiling joists--they tie the top of the walls to the "immovable object", the central masonry mass. They are attached to the side of the top beam with joist hangers, rather than setting them on top--made the ceiling come out right at eight feet..
The walls are fully compressed,(about 8 inches) which took a week of cranking all the nuts down a few more turns each day. After this, I laid one inch rough-sawn cedar over the joists, with sheetrock on top of that---easiest ceiling I ever rocked!!
Thats the metropolis of Silver City, population 200, in the background. Lake Tahoe is just over the blue mountain in the far background--about twenty miles away.