Did my truck have factory AC or not?

[Number21]

I recently got a 1973 K20 as a gift and and I heard second hand from the last owner that it had factory AC, although the compressor is missing as the engine has been replaced. I believed this because, well, I have AC controls in the dash. There are also some heavy hoses under the dash that are cut off, for AC or...?

On the other hand I know the firewall is different in factory AC trucks and I just noticed tonight that my '73 looks exactly the same as my non-AC '79. I also don't have the vents in the dash, but the pad has been replaced so I don't know if there was? So now I'm wondering if the '73 actually had factory AC? Can I tell by looking at the firewall?

I want AC, but only if my truck originally had it. I'll try to take some pics in the morning...