A/C O-Ring thickness + diameter

[Rob79er]

I want to the R134 switchover but its not real clear on the what is the "correct" O-Ring thickness and diameter that should be used for a given a/c connection.
My question: Is there a measurement out there that states that the different connections should have X diameter and Y thickness (for drier, evap, condsr. etc)?
Also is it true that the O-Rings should be dipped in R-12 mineral Oil before installing?
thanks

 

[LVMYVT76]

Most new o-rings work with both r-12 & r-134. I think they were green in color compaired to the black original ones. Yes, you should use oil on them, but use the oil that matches the freon you are going to use.