They are most often missing due to age deterioration. Makes your Buicks heater valve look OEM correct.
NOS 1968 BUICK LESABRE W/ AUTO CLIMATE CONTROL HEATER CONTROL VALVE 1385322
H2987 Heater Control Valve 1976-1980 GM Buick Olds Pontiac NORS
NAPA - HVAC Heater Control Valve #74609 - Fits Buick H249
HVAC Heater Control Valve for Chevy Impala Malibu Buick Regal Cadillac GMC Olds
For 1971-1975 Buick Electra HVAC Heater Control Valve 4 Seasons 1972 1973 1974
For 1964-1966 Buick Riviera HVAC Heater Control Valve 4 Seasons 1965