Does one use the factory A/C box when restoring a '65 Barracuda A/C ?

My '70 300 had all the underhood A/C bits and pieces missing.

I used stuff from these guys: Products: Air Conditioning - Bouchillon Performance Engineering to replace all the missing underhood stuff and then utilized the existing pieces in the car.

ac condenser kits - Bouchillon Performance Engineering will get you the condenser, hoses, dryer etc.

You'll need the brackets to mount the Sanden style compressor Products: AirCon Compressor Brackets - Bouchillon Performance Engineering and a compressor ac compressors - Bouchillon Performance Engineering

I also bought a vacuum pump and gauges from Harbor Fright so I could fill the system myself.

Having never really done any A/C work, I was apprehensive about doing this myself, but it turned out well and was easier than I thought it would be. I'm very pleased with the results.

Give them a call. Really nice, knowledgeable people to deal with.