Hey Guys, I'm after your thoughts here.

My car has been pinging lightly for a while now and I have been thought the process of trying to find the elusive vacuum leak. The pinging happens under moderate to heavy load at any number of revs. I changed the spark plugs a while ago to a new set of Bosch W8LCR with no difference.

The only piece of history that may be relevant is that the when I bought the car, it was running full rich all of the time and needed a new oxygen sensor to fix it.

I recently adjusted the valve clearances and it has become a lot worse. So I have pulled the intake manifold off to replace the manifold gaskets and get a closer look at the inside of the engine.

I've never pulled the head on one of these before so I'm not sure what is normal.

What do you think?? These are pictures of number 2 and 5 intakes which are typical of all.

Options that I can think of here are
1. Put it back together with the new gaskets and hope it goes away
2. Do a compression test and reconsider
3. Pull the head, get it cleaned, reseat the valves and replace the valve stem seals

TIA