[jhv48]

I had a cam go flat on me back in the 70's. If his is going bad, he will hear lots of valve clatter. As the cam wears away, the valve lash increases, along with the valve noise. The way I identified mine was to adjust the valves, then drive it till I heard lifter noise. Didn't take long. There was no noticeable change in performance, only noise. Then I measured the valve lash. Found several lobes were indeed disintegrating and needed tightening. Then I had the cam and lifters replaced.

If you're not hearing any valve clatter, probably not a cam problem. Check it out before you start pulling stuff off.

The symptoms you describe could be just an old fashioned tune up needed. I would investigate further.