{"product_id":"cold-case-gmt556a21-family","title":"1977–1987 Chevy\/GMC Truck Radiator | Cold Case GMT556A21 Options","description":"\u003cp\u003eChoose a Cold Case GMT556A21-family aluminum radiator for your 1977–1987 Chevy\/GMC truck. These are the 21-inch overall-height versions, with OE-style stamped tanks and two rows of 1.25-inch tubes. Match the radiator version to your engine, hose connections and radiator support before ordering.\u003c\/p\u003e\u003ch3\u003eChoose your radiator version\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eGMT556A21 — Silver \/ polished:\u003c\/strong\u003e Standard configuration for automatic transmission. Upper hose: 1.50 inches. Lower hose: 1.75 inches.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGMT556A21B — Black Night Rider:\u003c\/strong\u003e Powder-coated black, automatic-transmission configuration. Upper hose: 1.5 inches. Lower hose: 1.75 inches. Transmission cooler fitting: 5\/16-inch inverted flare. Supplier lists compatibility with the factory fan shroud. For 4WD\/1.75-inch outlet vehicles, the supplier lists lower hose Gates 20694 or Dayco 70664.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGMT556A21-1 — Polished, smaller hose connections:\u003c\/strong\u003e Automatic-transmission configuration with a 1.25-inch upper hose and 1.5-inch lower hose. Transmission cooler fitting: 5\/16-inch inverted flare.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGMT556A21LS — Polished, LS swap:\u003c\/strong\u003e Includes an LS-swap steam port, with 1.50-inch upper and lower hose connections. Supplier lists automatic-transmission applications and recommends an external transmission cooler.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShared construction and dimensions\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e100% TIG-welded aluminum construction\u003c\/li\u003e\n\u003cli\u003eTwo rows of 1.25-inch tubes\u003c\/li\u003e\n\u003cli\u003eOE-style stamped tanks\u003c\/li\u003e\n\u003cli\u003e16 fins per inch\u003c\/li\u003e\n\u003cli\u003ePressure tested\u003c\/li\u003e\n\u003cli\u003eCore height: 18.8 inches\u003c\/li\u003e\n\u003cli\u003eCore width: 28.35 inches\u003c\/li\u003e\n\u003cli\u003eOverall height: 21 inches\u003c\/li\u003e\n\u003cli\u003eOverall width: 34.33 inches\u003c\/li\u003e\n\u003cli\u003eOverall thickness: 3 inches\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eThe polished versions use corrugated fins for additional surface area and thermal transfer.\u003c\/p\u003e\u003ch3\u003eFitment notes\u003c\/h3\u003e\u003cp\u003eFor 1977–1987 Chevy\/GMC truck applications using the tall, 21-inch radiator configuration. Confirm radiator-support dimensions, engine\/accessory clearance, mounting points, hose sizes and transmission-cooling requirements. These configurations are not interchangeable solely because they share overall dimensions.\u003c\/p\u003e\u003cp\u003eFor the shorter 19-inch overall-height version, refer to Cold Case GMT556A rather than selecting a GMT556A21 version.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eSupplier warranty:\u003c\/strong\u003e Limited Lifetime Warranty.\u003c\/p\u003e\u003cp\u003eCALIFORNIA WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov\u003c\/p\u003e","brand":"Cold Case Radiators","offers":[{"title":"Polished","offer_id":52898762883352,"sku":"GMT556A21-GSWT","price":435.54,"currency_code":"USD","in_stock":true},{"title":"Black Night Rider","offer_id":52898762916120,"sku":"GMT556A21B-GSWT","price":473.54,"currency_code":"USD","in_stock":true},{"title":"GMT556A21-1 – Polished, 1.25 in upper \/ 1.5 in lower","offer_id":53010681037080,"sku":"GMT556A21-1-GSWT","price":435.54,"currency_code":"USD","in_stock":true},{"title":"GMT556A21LS – Polished, LS swap, 1.5 in hoses","offer_id":53010749096216,"sku":"GMT556A21LS-GSWT","price":439.54,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0735\/5324\/8413\/files\/GMT556A21_77_to_87_GM_Trucks_Polished.jpg?v=1792774715","url":"https:\/\/fastmontysgarage.com\/products\/cold-case-gmt556a21-family","provider":"Fast Monty's Garage - The Shop","version":"1.0","type":"link"}