This heavy duty all Aluminum radiator provides superior cooling for high performance applications. This is the most popular high performance radiator used in the Spec Miata class. It bolts into the stock location. This 6061-T6 Aluminum Radiator, with a 1-3/8' core, is probably the finest performing radiator you can get to replace your stock Mazda radiator. Due to it's uncompromising quality and efficiency, this is chosen by Mazdaspeed Motorsports as their race radiator for the Miata. Many people replace other companies 'performance' radiators with one made by AWR. AWR's competition radiator features No epoxy, all aluminum construction, Furnace brazed core, Multi-louvered Fins, Tig Welding, 6061-T6 aluminum alloy outlets and fittings. Pressure tested at 32 psi. 5503 radiator 13" tall x 24 3/4" wide x 1 1/4" thick core.