Here's a Drill press modification I made a while back. This is Part 1 of 4 and part 3 is testing the accuracy and 4 has a link to the plans. I've since replaced the hand crank with a Harbor Freight 3/8" hand drill. You can't beat the price, I think I paid $9 when it was on sale.
This modification keeps the horizontal reference when you move the table. You can use a center drill and step up to a 12" long reamer and everything stays lined up.