Cylinder Stud & Head Bolt KitStuds 8 studs with rounded thread roots, rather than flat, improving fatigue strength 4140 Chrome Moly studs, oil quenched and tempered to 39-44 HRC Positive stop shoulder allows for consistent installed height 180,000 psi tensile strength Head Bolts Reusable 14% increase in strength over stock Heat treated 8640 steel 200,000 psi ultimate tensile strength 8 - head bolts with integral washer Formed threads Cold formed head Compatible with both MLS & graphite head gaskets