This excellent new assembly is for the round recirculator GM heater. The used originals are usually impossible to repair. This unit includes upper and lower tank, attached outer band for securing to your large exterior metal housing and pipes for attaching heater hoses. Ready to install in your outer heater housing. NOTE: These are better than original because they are made to withstand the higher water pressure of modern engines. Over 600 sold with one return! Another quality restoration part from Jim Carter Truck Parts. The core is hand made with much time involved. Sold each. 8 3/4" x 8 3/4" x 7" round coreThe 1947-1956 Round Recirculator Heater Core Assembly is a crucial reproduction restoration part for the dealer-installed, cab-recirculating Harrison heaters found in Chevrolet Advance Design and GMC trucks. Because original vintage units are typically corroded beyond repair, these components are vital for maintaining factory-correct functionality and appearance.Core Technical SpecificationsPhysical Dimensions: Typically measures 8-3/4" x 8-3/4" x 7" or an 8" to 8-1/4" outside diameter with a 3-3/4" inside "donut" diameter.Inlet/Outlet Pipes: Features dual 5/8-inch copper tubes extending through the firewall to connect directly to standard heater hoses.Pressure Tolerance: Engineered to handle the higher cooling system pressures of modern engine swaps (e.g., small block V8 conversions), unlike fragile original low-pressure cores.