Part Type: Carburetor Float. 1979 GMC K3500 Engine: 5.7L V8; Primary; Carb MFG: R-4; Carb Model: M4MC;. 1979 GMC K3500 Engine: 6.6L V8; Primary; Carb MFG: R-4; Carb Model: M4MC;. 1979 GMC K3500 Engine: 7.4L V8; Primary; Carb MFG: R-4; Carb Model: M4MC;.
