FE rocker adjustment and it still ticks - now what

[Grubby]

I ran the engine w/o valve covers and probed for noise. I found 3 areas of interest. I turned the adjuster down another 1/2 turn just on those - no change. Then I backed off just over 1 1/4 turns (from my starting position) - same sound but louder.

There is plenty of oil flowing.

Disassembled the rocker shaft assemblies. Shafts are oriented with oil holes down. No cracks visible. There is certainly wear on the bottom of the shaft. It can not be felt with finger nail and I measured about .0005" less in those areas.

The rocker tips and balls all show some wear but not much. The ID of some of the rockers does show some fairly heavy wear. Oddly, it was not the noisest that had the most wear. Nothing showed signs of blueing.

I inspected each push rod. No contact to intake or anything else.

The distinct tick is in two lifter/rockers at the very ends of the shaft (front and rear) on the right bank and the lifter/rocker at the very end of the shaft (rear) on the left bank.

My guess is 3 lifters that do not pump up all the way and contributing overall noise by some wear in the old Ford rocker shaft assemblies. What do the experts think?

John