"Mike" wrote in message
...
Hi All,

The new grille is mild steel, I
assume, and I'm not sure how well drilling holes in the new one to
match the old one will work.

I'm thinking of getting a 16x16, centering it over the hole and just
drilling new holes in the sheetrock.

Pick one:
1) Shorter screws
2) Drill the steel. Good bit will go through easily.
3) Use the larger grille

If you decide to drill the frame, put a pice of wood behind it as a backer
for the drill bit to hit when you go through. .