Technically, it's not. The block is bored @ 3.91. That's it. The stroke it f the crank that gets dropped in finishes the math to engine size.
Admitting it is overbored further proves that it is just a wanker post. Asking further pushes the proof.
Your could have left it at 3.91 is moot.
The over bore over 3.91 to 3.94
& the 3.31 crank works out larger than 318. The rules allow an overbore, but it is not a 318 no matter what you do.
It doesn't matter what the block was born wand th or marked as.
If such was the case, th n adding a 4/0 arm and what ever overbore the block takes, and in some cases, a 4.0 bore can be achieved, would be OK.
How is a 4.0 X 4.0 a 318?
Outlandish? Not by your written thinking previously displayed.
The thread title and general idea of the thread and it's intended purpose is clearly shown early on.
How big is an4.7 in cubes?
No worries, not picking on you.
