Part Type: HVAC Heater Core. 1973 GMC K15/K1500 Suburban Engine: 4.1L L6 OHV; EngineVIN: Q; FuelSystem: 1BBL; with A/C;. 1973 GMC K15/K1500 Suburban Engine: 5.7L V8 OHV; FuelSystem: 2BBL; with A/C;. 1973 GMC K15/K1500 Suburban Engine: 5.7L V8 OHV; FuelSystem: 4BBL; with A/C;.
