Factory In dash A/C question

[chevyrestoguy]

My '64 originally came with in-dash A/C, but when I got the truck, all of the A/C was missing except the all of the dash pieces (which was weird because that's usually the first thing to get robbed). Anyway, my chances of finding those parts is remote unless I want to spend a ton of dough piecing it all together. The truck is pretty thrashed, and I want to get it together to make a dependable, usable truck. I live in the desert southwest, where we regularly get over 100 degrees during the summer. A/C is a must.

So, my question: Is there any way that a standard heater core box can be modified to look like an A/C heater core box? I realize that the A/C box has a few more ducts on the backside, but I can fab those. My plan is to utilize a factory appearing box on the firewall side and put a Vintage Air (or other brand) unit up inside the dash. I want to utilize the factory A/C outlets in the dash.

Any suggestions?