For 1977-1978 GMC P25 Radiator Cap API 75815WS Radiator Cap -- Standard; 16 lb

API 23TT59G Radiator Cap Fits 1977-1978 GMC K35 Radiator Cap -- Standard; 16 lb

For 1978 GMC P25 Radiator Cap 24915GXGZ Standard -- Relief pressure 16 lb

API 76WS14Y Radiator Cap Fits 1977-1978 GMC G25 Radiator Cap -- Standard; 16 lb

API 85MY39Z Radiator Cap Fits 1977-1978 GMC P35 Radiator Cap -- Standard; 16 lb

API 63QX56P Radiator Cap Fits 1977-1978 GMC G35 Radiator Cap -- Standard; 16 lb

For 1978 GMC P25 Radiator Cap 23595SZMP Standard -- Relief pressure 16 lb

For 1977-1978 GMC P35 Radiator Cap API 83822XB Radiator Cap -- Standard; 16 lb