"Perhaps your data is out of date ... "

The quote you link from the book is just plain wrong but that's not surprising when you look at who wrote it. The Grand Gallery is limestone and Dunn's claim for some of it being Granite is nonsense but it suited his outlandish theories.

Having found such a basic error in only the first few lines it didn't encourage me to take the rest of your post with any seriousness as even a little research would have got that correct.

You say you are only interested in the maths and there is certainly nothing in your post that has any relevance to Ancient Egypt.