Cue Paul Harvey. Time for the rest of the repair.
First is another photo of the bracket and shim. I used the two studs to hold the shim in place every time I installed and removed the master cylinder and bracket.
If you look closely at the slot around the master cylinder push rod you can sort of see how little room there was for the push rod to move side to side.
The last thing I wanted to address was the pedal height. Previously the pedal was about 1 1/2" higher than the brake pedal, which meant that I really had to lift my leg up on every shift. There was plenty of adjustment in the actuator rod so I just shortened the rod with the lower coupling nut as the upper one was as short as it would go. Now I had two pedals that were the same height. All good until I pushed the pedal down. Then the upper coupling nut hit the clutch/starter safety switch. Now I know why the pedal was so high!
I ended up machining one side of the hex off of the upper coupling nut to make clearance around the switch. Unfortunately I didn't get a photo of that.
I noticed that the upper coupling nut was 3/8" NF thread for the heim joint and the other end was 5/16" NF thread for the all-thread. To do this the PO put a heli-coil in the 5/16" end to reduce the size from 3/8". Pretty clever I thought, as I would have gone through the work to make a custom one off coupling nut.
In the second photo you see the clutch actuator rod with the two coupling nuts. Unfortunately it's all right hand thread, so no nice turnbuckle action. The arrow points to the area I machined off to clear the switch.
The heim joint has been ground down on one side to make it narrow enough to fit on the post and have the keeper hold it in place. The odd part is that the keeper will only go on with the ground off part heim joint against the pedal and the keeper against the unmodified side.
The last photo shows it all back together and working nicely. I've got about 50 miles on it and no leaks.
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Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help.

RIP Bob Parks.
1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo
If it breaks I didn't want it in the first place
The WMB repair thread
http://67-72chevytrucks.com/vboard/s...d.php?t=698377