There are fourteen boxes in the stack that sits back from the window. They vary in size, too. The Sixth-Floor Museum reproduced with some accuracy the stack and may have some dimensions on record. The boxes on display were manufactured for the Museum.
I recreated that stack in 3D but it's largely guesswork based on photo-comparison.
I'm trying to recreate it too, but a physical one to see how easy it is to maneuver in a tight space. There appears to be some controversy about whether there were:
3 Stacks of books: The order of this configuration is the stack closest to the east wall is 4 boxes high, next is 5 boxes high, next is 4 boxes (this is how it is laid out currently in the 6th floor museum)
2 Stacks of books: The order of this configuration is on the Studebaker map and is missing the eastern most stack of books, and also the box on top of the middle stack is missing ..thus reducing that stacks height from 5 to 4. Thus the order of the 2 stacks of books configuration (as per the Studebaker map) is 2 stacks each 4 boxes high.
Here is the Studebaker map:
This map places the 1st stack of books at 5 feet 6 inches from the east wall. This leaves a comfortable gap of 30 inches for Oswald to get in and out of the snipers nest. However under the 3 box configuration, this gap is reduced to 12 inches. Here is the 3 stack and the 2 stack configuration layout for clarity:
The 6th floor museum goes with the 3 stack layout, and some police photos show the 3 stack layout too (in contradiction of the Studebaker map):
The famous photo of the 3 cartridges also appears to show 3 stacks with the easternmost stack in the front foreground of this picture:
Having said that, the official photos for the Warren Commission showed a 2 stack layout (as did the secret service reenactment video):
The Hughes film, taken as the motorcade rounded the corner in front of the TSBD appears to show a 3 stack layout:
Therefore, i was inclined to believe there was a 3 stack layout. That means that the studebaker map is wrong. EXCEPT for one key dimension - the Studebaker map places its easternmost stack at 5 feet 6 inches from the east wall. Under the 3 stack configuration, this easternmost stack is actually the middle stack now of the 3 stack configuration. Therefore the gap for Oswald to get in and out of the snipers nest reduces from 30 inches to 12 inches.