You will have to drill 2 holes thru the firewall of a non-factory AC car for any type of AC compressor addition, unless you use the systems which replace the cabin climate box and route the hoses thru the big hole where your cabin fan used to sit. I suggested a Sanden because RV2 are getting harder to find, and that will only get worse, plus you would also need to source factory brackets to mount it to the engine. You may also need to change the crankshaft pulleys and others, as the belt routing varied over the years and between AC and non-AC cars. Buying a kit from Vintage Air and others is the easiest route, but expensive (>$1000). I spent ~$200 each for the AC systems I put in my three 1960's Mopars. Two had after-market systems from ~1970 with some parts I leveraged (knee-knocker boxes, York compressor w/ bracket).
