About the conversion to R134a....
I did mine, and it does take a little longer to cool. Also, I think I replaced the switch for the fan with a different part number for R134 vs R12. R134 operates at a different pressure and requires a different switch to kick the fan on. Please ask one of the techs to verify this though. The gray hairs on my head affect the memory sometimes, so I am not sure it is right.........
1989 560SEL (172k)
1989 325IC (122K)
2004 Suzuki Volusia LE (3500 miles)
2005 Yamaha Road Star (20 K miles)