Our gasket sets contain all necessary head o-rings to run our billet heads. These contain one inner and outer o-ring (OEM equivalent) to seal the outer head and dome to the cylinder as well as one dome sealing o-ring to seal the dome to the outer head. Dome sealing o-rings can also be purchased individually. These ship USPS so please expect 2-3 weeks for delivery. If you need them quicker please contact us.