Air Conditioner from a 73 to a 79

[blazerpro79]

Hey guys, I've not been on here for a while and I am about to do a few things on my truck, and want to check with all the experts before I go ahead.
I plan on swapping the A/c from my 73 C10 to my 79 K5 this weekend. My 79 had original A/C but a previous owner removed it. The AC in my 73 C10 has not been ran in about 25 years. I got an O-ring kit from LMC for the AC.

Do I need to decompress any of the old AC equipment, like it said, its been about 25 years since the ac ran in the donor.

I am going to bring it to a shop to get a service, and conversion to the newer freon, and then filled with freon. Anything else you recommend?

Any other comments are welcome, thanks
-Mark

 

[AZ79K5Project]

The newer freon on the existing condenser will probably not work. The R12 and R134A condenser's are different designs and sizes. The R12 condenser will not dissipate the heat necessary to run the R134 freon. R134A is not as efficient as the R12.

There are additional things that need to be done for the conversion.

I did a LOT of reading and research on a bunch of sites before I converted mine to the R134A. I replaced my entire system for the cost to replace the broken stuff on my R12 system.

It's unlikely that the old system has freon in it. It may though. If it is dry, the compressor may be shot as well.

My build thread (signature line) shows what I went through on the conversion.