I currently work in the Wholesale Radiator industry. (Trying to break into HVAC) I can't think of one aftermarket brand manufactured in the USA with the exception of copper/brass radiator cores. The cores however are usually two to three times the price of the import complete part. The only time I can sell a core is when the complete is no longer available or the radiator belongs to a large piece of equipment. Most of the time we are up against the part stores or internet where the bottom dollar wins. It's sad really.