Drilling new holes for seat belts

I am installing 93 front seat belts into a 88 GT. In my 88 the seat belt hole is a little lower than that of the 93. My question is, Can I use a normal drill bit to drill the hole? I ask because some of the seat belt holes actually have a small amount the thread for the bolt. Plus the metal seems thicker than the thread pattern. I dont want to screw up or create a unsafe scenario with my seats. Any one ever do this? Which route did you take? And what size drill bit did you use? I have a 27/64 drill bit that seems to be the size. Will that work?
 
Drill through the plastic panels and mount the upper part of the belt where it was originally. Then find a black grommet and plug the original hole.


Safer and easier than relocating the actually bolt mounting point. That's how i did mine.


Also, with the '93 belt, you will need to cut a hole for the mounting tab where the belt retract is. 91-93 seatbelts do not direct swap. You could sell them and buy 1990 belts which will direct swap