350z JWT Jim Wolf Technology Heavy Duty Valve Springs & Shim Kit

JWT race cams or JWT street cams with rev. limit raised above 7000 rpm need a stronger valve spring. The stock ones will bend, and cause engine head damage. The included shims replace the stock base shims to obtain the correct installed height (36MM). 43lb@on seat & 136lb@12.5MM lift with coil bind@13.5MM lift. 24 Valve Springs & Shims are included.