Quick questions. How many ounces of oil would an old A/C setup take (1983). It hadn't work for I don't know how many years. Got some newer hoses, had the system evacuated, and charged with 134a. Works awesome and want to know how much oil I should add in there to keep it that way. Where does the retrofit fitting go (r-134 style fitting), on the drier (accumulator)? Also, advance autoparts has some additive thats supposed to make 134 systems cooler, is it good, or a joke?