These popular headers fit 55-57 Chevy passenger cars accomodating GM 605 power steering boxes, most motor mounts and HEI distributor installations. Extra ground clearance makes lowered cars drivable and exhaust system installation easy. Available in plain or metallic ceramic coated. SB headers have 1 5/8'' primaries and 2 1/2'' collectors. BB headers have 1 7/8'' primaries and 3'' collectors.