The bolt that holds the pedal to the linkrod is special. It has a large bearing shoulder to enter the eye, and a reduced shank where it enters the pedal. The nut then retains it and the cotter pin is a safety so it can never fall apart if the nut come loose,......cuz that could be fatal.
Do not use a common bolt here, unless it was specifically engineered for this application.
The pushrod spec is .920 from the tip to the filter retainer