Where to find quality Shrader valves for R134a hi/lo ?

[r-mm]

There are many links for shraders for sale. I upgraded my 1989 BMW to R134a and am still chasing a leak. I want to replace the hi and low valves. Am I overthinking this - drive to NAPA? Plenty of kits on Amazon (although I already have an install tool)



Thanks

[r-mm]

I should clarify - the car came from the factory with R12. The valves I want to replace are on hard lines which I did NOT change when upgrading to R134a. Therefore I am not sure if I need an R12 or R134a shrader or if there even is a difference. I am talking about the core only, not the adapter to charge the system.

[r-mm]

I pulled the valve cores, they are as below and match the smaller size shown in this photo I borrowed from this amazon sale
.2" diameter
.8" long

I'm tempted to complicate my life by searching for the best cores available but having a hard time figuring out what to call this size valve to search for replacements. Searching by refrigerant is a world of confusion as one often finds R12>R134a adaptors and its very unclear if the "fit" mentioned is for the adapter which often contains a shrader, or the hard line itself that came with the vehicle.

[Tim]

Please, no Amazon links on this forum.