I know better than to use a Black Death kit for certain, but I was under the impression that a 134 conversion was safe if everything was disassembled, all the mineral oil thoroughly removed and parts flushed, and all O-rings replaced. Am I wrong?

On my truck, the air conditioning system is sitting in pieces at the moment preparing for just that (I had to remove the pieces to get the cylinder heads and camshaft out anyways ). I'm replacing the condenser with a parallel-flow unit, and the compressor is in good shape (and happens to be the same model used on later Ford pickups with R-134a installed from the factory), and I will be replacing the orifice with one from a truck equipped with factory R-134a.

Compared to spending $300+ to put R-12 back in the system, it seems fair to me, particularly since I'll be able to do my own work (except for recovering freon) on the system after putting it back together...

And, BTW, my 300D was converted to R-134a by the previous owner, and supposedly the job was done properly (I'm unsure on that, though). Other than a slow leak somewhere (had to put in a bottle at the beginning of this hot season), it's working properly after 2 years of me having the car and an unknown time of the previous owner having the car.

Tim, you are probably just fine doing what you describe.....it is the little things which worry me about the conversion. I have read, and I think it makes sense, that it is very hard to get all the oil out of the evaporator and the condensor without physically taking them out and being able to rotate them and flush in various positions.... and after sloshing the liquid flush around and then letting it drain one direction and then another...

Precisely. Which is why I recommend sticking with refrigerant that works with mineral oil - Duracool, HotShot, or my personal preference - Autofrost. That way there is NO issue with oil replacement. But otherwise it sounds like you're doing a pretty good job on the flush procedure, replacing the condenser with new eliminates one more variable.

BTW - why $300 for an R-12 charge? You should be able to get it for ~$25/can or $20/lb in a tank... it's just getting harder to locate.

Thanks to everyone for all the replies. I've been taking notes on everything being said. I haven't gotten a chance to do this project yet. It's been raining so much I can't get anything done outside. Hopefully the weather will clear up by Sunday soI can do this.

Thanks to everyone. I'll post a report about how it goes.

cmichalik