TYC HVAC Heater Core. 1987 GMC R3500 Submodel: Base Cab & Chassis; w/ A/C;. 1987 GMC R3500 Submodel: Base Crew Cab Pickup; w/ A/C;. 1987 GMC R3500 Submodel: Base Standard Cab Pickup; w/ A/C;. 1987 GMC R3500 Submodel: High Sierra Cab & Chassis; w/ A/C;.
