Hello, I recently put a new cam in my stock 84 GT. The new Cam is a CompCam 456 lift 456 exhaust 268 diration. I still have the non adjustable rockers. I also installed new Crane push rods that are .018 longer then the stock to make up for a reduced base circle on the new cam. I still hear a little valve tap when at idle. I was told that this could be the rockers hiting the baffles inside the stock valve covers. any ideas??