Not your normal engine knock

I'm not one to post a question in forums. I can find any answer with the help of Google. I have researched for hours and can't find one thread that matches my symptoms. First I have a SB 350 +.03, mild street comp cam, 650 DB, manifold, L31 vortec heads and headers. Not a daily driver. 100 to 200 miles a month. Noticed small blowby in July (has not gotten any worse), yesterday I drove to the store noticed run on or dieseling, Run on happened 3 times. I pulled a spark plug and noticed it was oil fouled. then today was driving 50mph (engine normal temp, oil pressure good) got a steady tink/knock that increased in sequence with RPMS. opened hood sound was coming passenger side valve cover. Immediiatly putted home at 25 mph then the knocking just stopped. The knock maybe lasted a total of 3/4 mile. In trying to diagnose I can't get the noise to repeat (luckfully). Normally run 92 octane +octane booster. This tank was run with no booster. Any ideas?

could be many things from a rocker arm . rocker stud getting cut threw by the rocker are you using the guided rocker arms .could be a guide comming loose. to a seat falling out of the head . valve freezing up in guilde to a lifter . if plug is wet some thing may came lose then went out the ex . could be part of the piston or part of a valve . seat . intake sealing good ? if that hole is realy wet could of lost the piston

I was going to chime in with:

What is a sticky lifter for a hundred, Alex.

Biggest thing I have learned in two decades of maintaining industrial equipment...it's near impossible to fix a problem which doesn't exist.

Just listen for it, and hope it doesn't come back

Think I'd be for doing a leak down check on the engine. The oil consumption and knocking noise could be separate problems, or could be the same problem!!! Leak down test are usually the "tells all" for cylinder condition!