OK. I've got a 377 windsor stroker in my 1988. I didn't build it so I don't really know whats in it. Recently I've been getting a noise like a hammer on anvil at about 1800 rpm which I thought was a cracked header. The car has a supercharger. That noise moved from the front of the car to the rear a few days ago. And now I've got a loud tapping noise, like a lifter, but much louder, from the passenger side. I think. I know the next step is to pull the valve covers. My question is, I've got Ford SVO aluminum heads. What should I be looking for? The oil pressure is good and it still runs real strong.