JB,
Chuck, Post #23, has mentioned some good things to check. It was mentioned earlier but may have gotten lost with all the other comments. As you have the side cam gear cover off, it is easy to check to see if the thrust bearing is OK. Move the cam gear forward by prying with a screwdriver. You should not be able to move it easily. If it does move easily you will have to remove the front cam gear cover and add a spacer under the spring for the thrust bearing. I use washers.
To check the center cam bearing, pry the camshaft up with a lever. It should not move. There is a lot of force from the valve springs pushing down, so it will take some force to push the camshaft up. You will have to have the pan off to do this.