these grommets are located on passenger side of firewall on my 67 rs.
were these for a under dash ac unit or what?
i have no clue but they appear to have been there from birth or shortly after...

http://i63.photobucket.com/albums/h148/yz222/unknowngrommits002.jpg

http://i63.photobucket.com/albums/h148/yz222/unknowngrommits001.jpg

I can't answer per-say but if you have a '67 aim book you can look up all the firewall punchouts and their uses...

geterdone, they look like grommets used in aftermarket air conditioning we used years ago. Probably for the hose routing into the car. It looks like they are just below where the heater core is.

i thought they were for a dealer installed a/c but wasn't sure,
these would be for a under dash unit , correct?
Ive seen one of those units 20 or so years ago, i wander if they worked good or not, if so i just might know of one taken out of a Chevy 2 that might be available to buy.
would they be the same?

Yes, under-dash. They worked fine. Just did not look built in at all. Very well might be the same. The engine brackets are probably different for 6 cyl vs. 8 cyl. Evaporator may be the same. Just needs to fit the bottom of the dash somehow.