Is the a/c in a manual 79 zx worth restoring to R12 setup? I've had two different mechanics tell me that the system isn't that well designed and would leak out in 2 years or so. If I go to 134a I'll need a new drier and compressor and the new hi/lo lines I put in may be too low pressure to use as well. I could get a R12 look-alike I am told however so instead of 134a I could go back to the lower pressure refrigerant I suppose. Is the there any particular history regarding a/c I should know about to help me decide? Thanks. Allen.