[screamin_c10]

Remember, barring catastrophic failure, the lobes don't just go round. They wear down over time and will still remain somewhat egg shaped.

With that being said the lifter will still move up and down in its bore and the rocker will still actuate the valve, just not as much as the valve-train on a healthy lobe. So even if you don't see anything as obvious as a rocker just sitting there motionless you could still have heavily worn lobes.

I would rent a dial indicator and check the travel of the rocker / valve on any suspected worn lobes.

Below is a pic of the cam I just pulled from a very good running 307 and it is very clear the lobes circled are very worn, but not round enough to stop valve actuation....The truck ran and idled perfectly at ~ 750 RPMs