my 72 gto dosn't have a/c but i have a 72 doner lemans that does....my question is, will that center a/c vent on the lemans come out and go into the gto bezel where the blank is?

The non a/c bezels are cast w/o the hole, so without cutting & glueing from the backside, no way the center A/C vent could ever be used in a non a/c bezel. For those looking for replateable a/c dash bezels, we usually have a few.