The Stovebolt Site Forums The Shop Area Engine Shop Knocking Noise

I've got a knocking noise in my 270 GMC engine. I've dropped the pan and checked the rod bearings and the rist pins, they all look good. I've pulled the plug wires one at a time with the engine running to see if the noise changes, but it doesn't. It sounds just like a rod knocking. I hear it most of the time but there are times when it stops for a few seconds. What else can I check?

Thanks, Tray