I just sent a friend a pedal off my 52 that has the little rod/cotter pin. He informed me when he got it that his 53 used the linkage that pops into the pedal. So,maybe they changed in 53???
Heck, maybe it was you I sent it to grin

1937 Chevy Pickup
In the Gallery
1952 Chevy Panel
In the Gallery
More photos
1950 Chevy Coupe
Pictures!

I'd rather walk and carry a Chevy hub cap than ride in a Ferd.
I can explain it to you, but I can't understand it for you smile