Dynatech slip-on race collectors offer great performance at an affordable price. All collectors come race-ready, to bolt on right out of the box. A unique feature is the pan e-vac bung installed on some equipped collectors. By using an 18mm thread, you have the option to use the included threaded adapter for your breather line hook-up, or oxygen sensors found on fuel injection and air/fuel ratio meters. U-tabs are jig installed for a direct bolt-on fit to all Dynatech Drag Headers. Available in a wide variety of primary tube and collector outlet sizes.