273/318 Offy Dual Four Barrel intake

I set the manifold on a 340 that has been decked, and everything lines up except for the bolt holes. It is a tight squeeze but I managed to get several bolts started. I would not hesitate to open up the bolt holes to the next fractional size to make this work.
As I mentioned, the port size is 1/4" difference in height and width from a standard 340 intake.