You know Manu I knew I had seen that number before. The coincidences only keep arriving.
The outside length of the coffer in the KC 89.62 inches = 6.789 Indus/Saxon feet 13.2 inches as 6.786 feet x 13.2 = 89.5752 inches difference with 89.62 = 0.04inch.
I know we are talking miles and feet and inches but it seems to always to come down to the number??? and 678 is a play on the side of the pyramid 687 Indus feet.
Anyway food for thought.
And a circle inscribed into the base of the GP with a side of 687.5 Indus feet is a circle with a circumference of 2160 (the diameter of the moon in miles).