The part number 370536 is widely recognized as an Original Equipment Manufacturer (OEM) part number for the main grille assembly of the 1977-1980 Chevrolet C/K series trucks, including the Scottsdale trim level.
370536: This is the core GM (General Motors) part number that identifies the specific design of the grille (the silver shell and insert assembly) used on the Squarebody trucks of that era.
"OEM" and "Original": Yes, when dealing with classic car parts, a GM part number in this format indicates it was an original factory part used by General Motors.
"CAV.1": This suffix usually refers to a Cavity Number or Tooling Revision mark from the original manufacturer's mold. This is a common feature on OEM plastic or stamped metal parts and helps the factory track which mold produced the piece. It does not change the core part number, but confirms it is an authentic GM-stamped component.