The L19 head stud upgrade comes with Studs, Washers, and Bolts for a complete installation. No Modification to your cylinder head or block is required as these are a direct drop-in replacement for the OEM head stud! The L19 upgrade has greater clamping force than the upgraded head stud kit that we have developed in the past and over 1000psi more clamping force than standard ARP Head Studs. They are made of aerospace alloy that is also used in Funny Car and Top Fuel Dragsters. With a yield strength of 230,000psi and a tensile strength of 260,000 these will hold the high horsepower numbers you put down with your VQ35 motor. We have held in excess of 1400rwhp with the L19 design in many different motor applications.