oil line o ring

[willy wagon]

in working on two majors i find the o ring under the head gasket on the oil hole is missing in both kits. i asked the supplier if they do not use that ring anymore. what thought on this. the manual says to put it in. can i use an ordinary o ring? thank-you

[willy wagon]

talked to the supplier of the parts they are sending the oil o rings. they do not come in the gasket sets.