I got concerned with the difference in pedals when considering a future brake vacuum to hydraulic booster swap. So I got myself a pedal from a Suburban K20 Diesel -89 with th 400. This truck had the booster rod code 71217 and the stud measured 14.1mm or a hair from 9/16 (14.4mm).
Underneath the green plastic bushing there is a steel bushing also.
I got the spring also that pulls the pedal back in position.
The pedal has number 355561 stamp in it.
