55.2-59 Changing rear axle lugs

[8man]

I have a ZR2 rear axle, and I've started rebuilding it. The lugs on the rear are metric and don't match the ones on the front hubs I got from TCI - 7/16 x 20. After talking to TCI and having the axles out of the tubes for the rebuild anyway, I decided TCI was right and it was going to be easier to replace the rear metric lug bolts with 7/16 x 20. I measured the knurl and got some from Summit that have the measured knurl size of .557".

Now, I need to drill the hubs out, but I talked to an axle shop today and they said the real problem was centering the new hole.

I thought I could just use a drill press, and using the right size drill bit, it would follow the original hole and be centered. Am I missing something?

Thanks.