Cam walk on a 258?

[OneMoreJeepPlease]

I looked on here for information regarding camshaft walk on a 258. I remember reading about it sometime before but am unable to find any information on it now. What is occurring on my 85 with the 258 it feels like the distributer all of a sudden detunes or retards for no reason. It just feels like a loss or power. It doesn’t sputter, die, or back fire.
Info for inquiring minds.
1985 258 in a J10 PU with the 998/999 AT.
Upgraded carb 2150 from a 1984 Ford 304
Stock Motor craft Ignition, with upgraded Ford 300 wide cap and rotor, upgraded wires, and replacement coil from a 91-94 Cherokee 4.0. Everything rechecked and traded for off the shelf (my own parts collection) units before and after this occurred with no change.
Distributer has been replaced with a new unit since this started with no change.
All gas filters are brand new / changed since this started with no change.
The problem occurs under all load situations except for Idle (it may happen then also I just can’t tell because the vehicle is not moving).
The problem only occurs once the vehicle is fully warmed up (15 to 20 min)
It doesn’t stay detuned but seems to cycle back and forth but not in a consistent manner.
Any help as to what to look for, or at, or if it is my cam what can be done to fix it short of a rebuild would be greatly appreciated.