PAC 1219X Valve Spring as used on M-6049-Z304DA Cylinder Heads O.D. Large End (in) 1.207€ I.D. Small End (in) 0.650€ Installed Height (Valve Closed) (in) 145 lbs. @ 1.800€ Open Valve (Valve Open) 358 lbs. @ 1.175€ Spring Rate 340 Max Coil Bind (in) 1.100"