I pulled off the grill and headlight trim on my 83 to paint them. When I did I found two identical holes in the frame to the left and right of the radiator. They are round and are near the headlights with one having a removable plastic cover and the other being cut out but still held in place by a little uncut metal. This model came with square, over and under headlights so it's not for lights. There's nothing behind them for servicing so I don't have a clue. If they were cut for extra ventilation, why put a removable plastic cover on one of them? I'm thinking I might kick them out and add round beams to shoot through the grill. (like I need more lights)
Anybody know what they're for?

 

Is it those like 5 inch holes with little square tabs on them? I think that's for the air intake hose to the carb maybe the diesel engine goes to one and gas to the other

 

Nevermind. Thought this was about k5s

 

Is this a K5? I don't think any 1st gen s-series ever had over/under headlights...

If it is a K5, then they are just as abig84 said, for the intake.