I used RedTek in my 86. After the front-end fire, I received reports from the fire department, and the police that while they were attempting to extinguish the fire, there was a large explosion. My first thought was fuel rail, which they assured me it was not, and that my fuel lines had ruptured before they got the hood open, and had the fire mostly under control.

Turns out, that RedTek (R12A) is highly explosive. The line going from the low-pressure hard line on the driver's side fenderwell to the compressor had gotten hot enough to melt, and as they almost had the fire out, it ruptured. Made quite a mess, and threw bits of burning plastic all over the place.
From there, it acted like a blow torch. Hot enough to melt my AFM into a puddle. The fire department was quite amazed at this.
From what they say, there was the initial explosion, and it then burned for 10 or 15 seconds after that.

After that experience, I will never run a hydrocarbon refrigerant in any of my cars. I have R134A in my 951, and once I get it recharged again, I will continue to be very happy with it. I had an O-Ring fail a few minutes after having it recharged. It was really nice for about 5 minutes, lol.

So, for the sake of the local F.D., don't run a hydrocarbon refrigerant :)