Richard's car not having them may be because his higher VIN, but then again, his is a 1SS with an AT and Davis and Snook's cars are both 2SS/MT cars, so I guess it's possible that either the 2SS package or the change in tranny is responsible too?
Camkid54's answer sounds the most plausible to me, though it would be nice to get some verification.
US Navy retired submariner.
previous cars, starting with my first.
1967 RS/SS Camaro
A long, undistinguished line of sedans, SUV's, and minivans.