[Andy4639]

I have 134-A in my 71 C10 and 64 SS Impala and they both will freeze you to death if you run them on high. The people who state R12 is better just don't know. R134-A will cool as good as R-12 and it's better for our world so they say.

Things to know though.

Block off any way air can go around the condenser & radiator, this is a must on any system. You want the flow going through them not around them.

You need the system setup right and don't skip anything.
The major thing is a good compressor that will cycle. The old ones that are for these trucks just aren't the ones to use unless you just want the right look. In the long run they want hold up for everyday use. I tried 4 of them and just gave up. I tried used, rebuilt, new you name it they all failed.
Buy a good quality compressor.
Here is a link to my upgrade in the C 10. I had them do away with the drier though not need with the accumulator I already had.

The pictures of the outside & inside temps was it sitting in the garage. With a fan blowing on it. When driving it will drop to 36/38*.

https://www.originalair.com/67-72-ch...t-134a-stage-2