[Rust-O-Matic]

I pulled the valve cover this weekend, and you can clearly see the two rubbed spots inside of it from the tips of the (stock) rockers. I pulled the first two rockers and inspected the parts. Pushrods are filthy but straight and oil runs clear thru. Nothing appears to be bent or loose.

So I decided to turn the valve cover around 180 degrees and see if there was more clearance. Nope. I could actually see the sheet metal move every time the rockers moved as it idled. So I took it back off and dented that area out just slightly with a ball peen hammer. That actually stopped the contact between the valve cover and rocker arm tip, and I could no longer hear it with the stethoscope.

So then I started it back up and listened to the fuel pump again with the 'scope. No noise, but the engine was still cold.

Then I took about a 10 mile ride to get some gas, and as soon as it was up to temp it started ticking again. When I got back home I left it idling and put the 'scope against the side of the valve cover I "massaged" with the hammer and it sounded just fine. No more loud clicking.

Next I listened to the fuel pump and it was clicking like pretty loud through the stethoscope now that all was warmed up.

So I still don't know exactly what the problem is, but I've got a new Delco pump coming my way, and I'm probably gonna find some different valve covers. I don't know if there's a reason the rockers were rubbing, or if it's just because of the poor fit and quality of that particular cheap aftermarket valve cover. I think I found this pair of covers in some boxes of old parts and junk. I don't even know where I got em, but I'm sure they're second hand.