OER Parts offers a wide selection of Cruise Control Components for your 1977 GMC C15 Suburban. OER Parts offers 1977 GMC C15 Suburban Dash Mounted Switch Cruise Control Unit For Use with Non-Computerized Engines, 1977 GMC C15 Suburban Dash Mounted Switch Cruise Control Unit For Use with Computerized Engines, 1977 GMC C15 Suburban Column Mounted Cruise Control Unit For Use with Computerized Engines, 1977 GMC C15 Suburban Column Mounted Control Cruise Control Unit For Use with Non-Computerized Engines, and 1977 GMC C15 Suburban Universal Cruise Control Handle.