How to difference between R12 & R134a fittings assume?

[torchdgt]

I bought a setup from a guy off his 88 stang and he doesn't know if it was R12 or has been converted to R134a. So aren't the fittings different or something like that?

[BP]

Fittings are completely different. R134a ones are shouldered and use a quick release setup, R-12 are regular schraeder valves.