The visible ones that don't leak, look like the one in post #6.

Does anyone have the part numbers for the gaskets? I just had a pressure washer repair shop redo the hoses on my oil lines and when I asked about the o rings and gaskets, I was told to "just bolt everything back together and you'll be fine". I have my doubts about trusting a small piece of rubber that's 25 years old & seen half a million miles.

Search rock auto for your year/make/model and look for oil cooler lines and you will find the o-rings ect.

most auto parts stores carry them. Oriellys part # 66201 - help area dorman seals - also I got the part # off the Oriellys web sight on the net so it will bring up several different parts but the seals will be one of them