1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 VALVE SPRING

Part Number: 91-524

VALVE SPRING - Part Number 91-524
This kit includes Thermo-Cool coated springs and titanium retainers installs at seat pressure of 145 lbs. Crane Cams. The stock Evolution springs average 130 lbs. seat pressure and are marginal in height even in the stock engine. With any cam change they should be checked to be sure there is no coil bind (collapsed to their solid height). By installing either of Crane's 145 lb. spring kits (part No. 91-522, a valve lift up to .510" can be used without any machining to valve guides. Up to .675" valve lift can be used if valve guides are altered. For more pressure use spring kit part No. 91-511 or 91-523 which install at 175 lbs. at the valve seat. These kits will accomodate a .625" valve lift with only modification to the valve guide for seal to retainer clearance.
Thermo cool w/titanium retainers 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974

Purchase