1965/72 F100/350 all engines, 3/4 speed transmissions.

The clutch adjustment rod is composed of two pieces:

DOTZ-7521-C .. Release Rod-3 29/32" long.

DOTZ-7A504-A .. Rod Extension-2 27/32' long.

The rod attaches to the Z bar. The extension slides over the threads of the rod, its pointed end fits to the clutch fork. The rod is double nutted, loosening/tightening the nuts adjusts the clutch.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
From the pedal to the Z bar is the clutch release rod (C5TZ-7521-B 18 7/8" long-1965/66 F100/250 2WD), has 90 ends which use nylon bushings (COAZ-7526-B).

The bushings crack apart, fall off. The 90 degree ends begin to bend, then crack, then snap off. The rod is obsolete, no one repro's it, NOS or good used is as hard to find as Jimmy Hoffa.

So, you want to make sure the nylon bushings are in good shape. Otherwise...
---------------------------------------------------------------------------
The Z bar attaches to two pivots, one on the frame (C5TZ-7521-A), one on the engine side (C5TZ-7A535-A - I-6 only). On each pivot is a nylon bushing (C1AA-7543-A).

The bushings crack apart, the Z bar flops around on the pivots...eventually the studs of the pivots the bushings ride on snap off.

When you replaced the clutch, did you replace any/all of these bushings?