I agree
I don't know very much about AC systems, but from what I've read, the single most important consideration is the condenser. It seems that most of the older R12 condensers are not able to get rid of as much heat as the newer ones designed for 134A. I recently converted my '87 vette from R12 to 134A and it works fine, but it's condenser is already of the newer design. The newer small aluminum pumps seem to pump plenty of refrigerant and require only 2-3 hp to do it. I have not heard anyone say the evaporator (AC unit)will be a problem in a conversion. All the hoses, accumulator/driers, etc. now being sold are 134A compatable.
Here is a great site that I recently found that can help get your AC up and cooling.
http://www.ackits.com/forum/index.cfm
