72 Chevy Air (Help)

[reasonover]

Does anyone have the measurements of the original air vents on both sides of this truck, I'm trying to install a stock air unit from another truck into mind that did not come on the truck new.I need the diameter of the hole to cut and the measurements from the side and from the bottom. All you would have to do is to take out the (2) bottom screws and remove the air vent bezel to measure this. There may be somebody out there that may know a book that may have this in it.

Thank you in advance
David