That sounds more like rod knock. Best way to determine if it is rod knock is to drain the oil, drop the pan when its hot and wiggle the bottom of the rods at the crank.

All of the rods are in place and don't give way.

Diagnosing sounds like this via the internet is not an easy task. Probably the only solution would be to either completely strip the engine down to the block and measure everything or take it to a shop that can precisely diagnose the noise. That'* about the only advice I can offer at the moment.

Thanks, Mike. I'l look into that. My mechanics instructor put his hand on the valve cover and felt piston 1 'slapping' the cylinder head. GM engines are notorious for piston slap if you starve them for oil. The first owner starved the engine at least 4 times, according to the service reports acquired by the dealer who sold the car to my grandfather. I'm thinking of just installing new pistons, push rods, rings, basically the whole nine-yards because the block is still solid and I can easily get another 200,000+ miles on my cylinder heads.

This is a FIRST I have ever heard a 3800 slapping a cylinder head.

As crazy as it sounds, you can actually feel the piston slapping the cylinder head. the piston will end up breaking after my engine odometer hits the 400,000 mile mark.

What do you plan on doing with the engine after she "goes"?

Piston slap is not the piston hitting the cylinder heads. It is when there is too much clearance between the piston and cylinder walls and the pistons rattles (or slaps) against the walls as it moves up and down.

A piston physically contacting the head on the top of its stroke can only happen if there is a chunk of something sitting on top of the piston, there is a grossly excessive build up of carbon, or you are using the wrong spark plug and it is too long.

If it is piston slap, one band-aid fix (well, more of an improvement than a fix) is to run a heavier grade of oil. If you are running W30, go to W40. If you are running W40, go to W50. This should reduce the slap.

Probably custom order a new small block and continue with it. I love the 3800NA but now I want a Supercharged 3800. Plus, I want it to become my next project