Lefty, your writing skills show poorly. Spelling is off. While no one is exempt from bad spelling and poor diction, your excelling at it. After reading your post three times, I think I can answer your questions. If indeed it is a question and not just a rambling statement.
Yes. Many of the race blocks were cast with a bore just smaller than there listed 3.91. It was a rough bore. Needing finishing. The cylinders thickness is listed in the parts book. These race blocks ether have a “X” or a R followed by a number to identify them. Like below. There is also a casting number on the drivers side at the rear above the starter. This number can be looked up in the parts book to exactly what it is.