Street, I had the same issue as I recall. Not elegant looking, but it doesn't matter, it's covered up. The holes do not have any function if they are larger than the bolts. The only thing on that spacer that matters is the registration ring that centers it and the tranny in the bellhousing .. and of course the thickness of it. Drill on .. you need to discover the *next* problem
No, I don't know what the next problem will be, just that this car building hobby is a serial process of problem solving
Sam