As you know I have the MY at 2.75 imperial feet. And I think I have shown how this 2.75 could work with Stonehenge.
Stonehenge and the Great Pyramid do have numbers in common and the diameter of Stonehenge measured to the center of the Sarsens as given by Gerald S Hawkins = 99 feet 1 inch. The Great pyramid when folded out laid flat has a radius of 1/2 base 378 + slant height 612 feet = 990 feet. The diameter of Stonehenge then is 1/10th that of the GP radius.
Dividing 990 feet by 2.75 = 360 MY and this is significant. In addition re the use of royal cubits 280 and 440 of 20.625 inches give .
height 481.25 / 2.75 = 175MY
base 756.25 / 2.75 = 275MY