Not knowing for sure, but I would bet the cam should have a alternating taper, this would tend to keep it in the center and not force it to one side.
Glad you know about the rotating lifters, thats the fastest way to tell if a cam is good. I just pulled apart a Pontiac with half the lifters ground down. They quit rotating sometime ago, each one looks like you heald them up against a grinder wheel!
Joe
