As stated before the primary holes are smaller than the secondary holes on the intake. Remember that the factory had a bakerlite type spacer about a 3/8 thick between the carburetor and the intake. I have measured a bunch of intakes and have only found about .020 difference in all of them. There is no printed spec on these holes. we use to open them up a little on our stocker stuff since there was no printed number. They would check them and compare to others and I guess we were never to big. I think we opned them up about .030 on both. The other thing you will find is that they are not always on center with the 4 carburetor bolts. Factory tolorances are not always the best.
Good luck, Keith Craft
