Chevrolet Performance Thermostat Housings feature extra thick bases and cast aluminum construction to prevent leaks by minimizing warpage. They are designed to be high quality OEM replacements for small and big block Chevy V8 and 90 degree V6 engines. The chrome version includes chrome bolts and a leak-free neoprene o-ring seal to pack a visual punch and dress-up your engine compartment! Add a high flow thermostat to keep your vehicle running cool.