I was not expecting this until Monday, and I made some weekend commitments that will prevent me from tearing into this straight away.
Stay tuned though!
Oil Capacity & Refrigerant
I emailed the AC supplier Mike O. from Classic Auto Air in FLA, and he called me back.
So far this guy has been a huge help on this project.
It's pretty custom and not many suppliers will help with piecing a system together. I'm very grateful.
Here are notes from my call with him.
Oil
Using the chart above the dual air system uses 3 ounces more than a single system.
He said that the compressor comes with all of the oil needed for it to run properly; however, since it's a dual system adding an extra 3 ounces of oil is probably a smart move.
The explanation for this was the evaporator in the rear does not travel any oil and in front it is a plate and fin design which can trap some oil.
The accumulator collects some oil in meters it somewhat.
Conclusion: add 3 ounces of oil to this system with a new compressor that is already full of all oil.
Refrigerant Charge
Typically when converting to 134a you use 70 to 80% of the original charge amount. (as a reference)
However in practical application he said to add 2 pounds into the system and run front and rear on high full blast for 30 to 45 minutes and measure the temperature, front and rear.
After seeing what the lowest temp. you can achieve is, add 1 ounce of refrigerant and wait 5 to 10 minutes to see if your temperature drops more.
Repeat this process until the temperature no longer drops. And you're done.
Record amount of refrigerant for future servicing (because no one will know how much to put in)
Note that this uses a parallel flow vs. stock will impact how much refrigerant to use.
Other things
When charging and testing the system just let it idle, driving it is not recommended.
Lube o-rings with Oil before install (comes with oil)
Attache fittings by Tighten them by hand and then with
two wrenches tighten them 1/2 to 3/4 turn more. Don't over tighten, it will pooch your o-rings.