Lambda Tower
 

I keep finding my mixture to be changing after it has been set. I can set it fine via the tower and I can feel the spring inside there return the portion that engages the adjustment screw back to the upper position. But I still find that the mixture does not hold and will wander to a little rich or a little lean about a week after driving. My question is two fold. Does this signify I need a new adjustment tower? Or does this suggest that there is something else wrong in the distributor? My AFM is set perfect as well and I do not think I have any air leaks into the AFM to throttle plate section as when I spray carb cleaner all around it I do not get any fluctuation in engine RPM. What do you guys think?

It sounds like normal variation with atmospheric conditions. Once the O2 sensor warms up enough to "kick in" the mixture will hunt around slightly above & below the correct mixture.

Want some great fun? Hook up your duty cycle meter with longer leads & drive around with it sitting on your dashboard.

No not normal wander due to temp or O2, but actually moving in to Rich or Lean area so I have to re-adjust to get back to center area. It will move from perfect %50 to say %35 or %65. So I need to bring it back via the control tower to the right place.