The aluminum radiators have the end tanks tig welded on with filler wire and that leaves a noticeable fillet weld where those rubber isolators mount. The new rubber isolators fit on the edge of the stock c/b radiators like jello fits a mold. As they age and bounce around for years they don't fit so well, or look that good. A cooling system is comprised of six main parts: Radiator. Thermostat. Water Pump. Hoses and valves. Inlet and outlet tanks. Radiator cap. Your coolant is designed to absorb heat from the engine block. Coolant is pushed through the engine block via the water pump and then through a series of fins and tubes inside the radiator that allow the General Requirements. Importers and manufacturers of intentional radiators and other devices that require certification must fulfill the following requirements: 1. Have an authorized test lab carry out compliance testing. 2. Obtain an FCC Registration Number. 3. Obtain a Grantee Code. 4. Dex-Cool Antifreeze Coolant was introduced by GM in the 1990s and promised super-long coolant maintenance cycles—but suffice it to say, the antifreeze wasn't an immediate hit. So we went in to do some more research on Dex-Cool and came across this video from the engine experts over at Mahle. The video goes into plenty of detail on DexCool 9iUxo.