340 bored over 0.030 inch and stroked 4 inches

yellow rose said
Technically, and every sanctioning body I'm aware of, says once you go past the whole number, displacement is the next whole number.

So.........technically speaking, the op's engine is 417 CID.

In math if the last number is 5 or more, you round up...

If the last number is 4 or less, you round down...