I've had the same experience... and I never bothered to search for correct ones.
BTW - if you do find some... please post where you found them. Thanks.
1969 Camaro SS, 350(NOM), M21, 12 Bolt Posi, 01B LOS Build
1977 Camaro, 350(LM1), M20, 10 Bolt Posi, Purchased New, (SOLD)