Thread Size M14x2,0x152. Elring Cylinder Head Bolt Set. Why Choose Elring?. Bolt Head-/Nut Design Male Torx. MAN: 51.90020-0383 MAN: 51.90020-0383 (8x) MAN: 51.90020-0465 MAN: 51.90020-0465 (8x). Check your vehicle's specifications match the compatibility list below.