This fits the 1947-1948 Chevy Trucks With Outside Air Heater and Defroster and 1950-1952 Chevy Trucks with the Airflow Style Heater and Defroster.  This also appears in GMC trucks.  We have seen this heater core as late as 1955.   THE TUBES ARE INLINE.

The "Air Flow" DeLuxe heater used fresh air supplied from a duct that took in air from the outside. The lower priced heater was the "Recirculating" heater used the in-cabin air and had the round donut style core.   Its most commonly found in southern "mild climate" cars.

We have replaced the cellular Harrison design with tube and fin core that can handle the higher system pressures of today's engines. 

Heater Core is 2-5/8" thick.