On further searching looks like they are 3 1/2 at standard so think that must be what I have if I add on .005 for the accuracy of my gauge.

Seems pretty amazing to me that after 70 years (the numbers show it as a 43 engine) it's still at STD bore, or maybe that's what my issue it?

For those who believe, no proof is necessary.
For those who don't believe, no proof is possible.

41 Chevy