Biker, you are the one who is clueless. Point is that the space in the bottom end of the BBC casting, tall deck or short, does not have an unlimited room for stroke and are in fact the same, the tall deck engine can't be built any bigger than the short deck engine using a stock 4.25" bore GM block.
Your V6/V12 idea holds water about as good as a screen door works on a submarine.
You can speculate about engines all you want, but stop offering advice, 85% of what you are posting is pure crap and will confuse those who are trying to learn here.
You need to join those learners.