The cast iron torqueflite and 727 starters do not use a shim. They have a plate that goes behind the starter to block an open area where road dirt could get
in. They have nothing to do with starter engagement. GM cars use shims because the starter is mounted to the block, and manufacturing tolerances vary. Chrysler starters bolt to the transmission, needing no adjustment. Most probably went missing the first time
a tranny or starter was changed.
