I have re-checked the block casting number and it is definitely 3789716. I am aware that a 235 might be 3739716, but the raised casting number is very clear and not fuzzy at all and the third digit is definately an 8, not a 3. The stroke is right at 4" so maybe the Inliners information is wrong and the crank has been reground as you suggest. The bore is 3 9/16 which would support this.
