"The roll pin should be held b
"The roll pin should be held by friction, between it and its bore thru the flange. Normally, I'd expect them to move when persuaded with a punch and hammer (I can say this is a routine operation).
It could have sprung into the pan but I'd say that is a remote possibility. If it did, I'd be incline to let it lay. If its on the windage tray it won't stay there for long.
If they are original, I'd say they are both overdue for replacement. its not unusual for them to go 10 years with moderate use, then again, i've seen them fail in under 200 hours.
Why you have it out, check the push rod for wear and the cam lobe, too, if you have the measuring tools. The rod should be 5.76" and the lobe lift (rod movement, axially) should be 0.344", for a stock cam. There's a plate between the block and pump that will need to be pulled for the rod to come out. also, a thin grease on the rod will help hold it in its slot during reassembly. Also, you may find it beneficial to rotate the engine to get the rod on the low spot of the cam to make reinstallation easier."