1973 valiant 318 car stalls when compressor comes on

I finally figured out the problem with the air conditioning system I was able to get the valiant to the house the timing was off I had to advance the timing air conditioning is working but I still have to fine tune it but it's getting there thank you
OEM timing spec is probably about 10 btdc. About 14 btdc works better with todays fuel. You'll probably need to lower the curb idle a tad with the timing advanced.