Chevy Gen III LS Series Small Block (2003 & earlier), CA 625+, 4 short, 16 long, Natural Finish, 12-Point Nuts. 
 
All custom age 625+ studs are centerless ground, heat treated prior to thread rolling and machining and are rated at 270,000 psi. These studs deliver a 60% increase in tensile strength over the oem style head fasteners.