Bob, I had the same problem with a resto block about 5 yrs ago. I pulled all of the cam bearings, ran a light force brake hone in each bore for about a minute each. I replaced the cam bearings and everything spun real nice. Also what I have seen in the past depending on what bearing install tool you are using, sometimes a small ridge forms on the outside of the bearing, thats when the old cam with a groove in it trick works well.-Randy