Jimmy, I know you are being honest about your memory problem... so even though you regularly use the phrase ' R12 mafia' and clearly intend that to include me... I will restate the reasons not to go with anything except R134 or R12 in your automobile.
Freeze 12 is a blend... so the likelyhood of finding an Automotive AC shop who can help you in the future is very very slim... Think ' out on a vacation trip and the AC quits'....
Freeze 12 may or may not be as compatible with the oil being used.. which may mean it decreases the life of your compressor. When a blend does leak it does not leak in the same proportion it originally existed in... and that has the same potential with regards to oil movement. Our Delco Scotch Yoke compressors have no oil sump the way your vertical piston types do.. so the oil movement around the system is more critical to this type compressor.
R12 and R134a have plenty of history as to working right in systems designed for them... but we have systems designed for R12. Since the price of R12 has come back down from what it was several years ago... and the license to buy it is cheap and easy to get... It really does not make much sense to switch to anything else. But if you DO switch it needs to be to R134a.

If people would take my advice about learning first... or even doing a good search of my posts from the past you would find that I have stated in no uncertain terms that using the sight window to determine the amount of refrigerant is NOT legit.

Why is that important ? Because using the sight gage can allow you to OVERFILL your system . Why is that bad ? Because your AC works on differential pressure... even one ounce more than your system needs and the compressor has to work much harder to provide the same cooling...
Your AC will work well at many ounces less than max than even one over.

Where do I get that kind of information ? The same place I preach from all the time... the Mercedes Benz Factory Shop manual on Climate Control.

Keep in mind that Diesel Giant SELLS Freeze 12....
I have nothing to sell and only post because I hate for unsuspecting people to mess up stuff based on biased information.