According to our good friend mr Miesk, the refrigerant oil specifications are as follows.
When replacing other components of the air conditioning system, measured quantities of the specified refrigerant oil should be added to the component to ensure that the total oil charge in the system is correct before the system is operated.
Clean refrigerant oil should be poured directly into the replacement components as follows:
A/C evaporator core (19860): add 90 ml (3 oz.).
A/C condenser core (19712): add 30 ml (1 oz.).
Suction accumulator/drier: drain oil from removed accumulator/drier. Add same amount plus 60 ml (2 oz.) of clean refrigerant oil to new suction accumulator/drier.
If any other component such as an A/C evaporator core orifice or a hose is replaced, an additional 59 ml (2 oz.) refrigerant oil is necessary unless a hose bursts with a fully charged system. Then, the addition of refrigerant oil may be necessary with the amount to be determined by the technician. The suction accumulator/drier should also be replaced under these circumstances. Add an additional 59 ml (2 oz.) refrigerant oil to a system with a refrigerant leak.
My full thread on my AC repair can be found here.
And for a system where every component is replaced, what I learned is to take your new compressor, get a measuring cup, then mount the compressor so that the ports pour into the measuring cup. I let mine drain for several hours just to make sure the vast majority of the oil was out. You will need to periodically need to rotate the compressor pulley to get the oil out of the rotary vanes. 3 or 4 turns every few minutes should do it. My compressor came with a tag on it saying it contained all the oil for the system. The total oil should be 7 ounces for a stock 94-96 R134a System. Other years I have no idea. Ususally I tell owners of 92-93 broncos to go with the complete system for a 94-96 and it should all be great. Other years I have no clue.
I got a full kit for the compressor, came with all these items.
Once its all out you should have something over 5 to 7 ounces of oil.