Ferrea is pleased to offer our Pro-Series Titanium Retainers including sizes that fit both traditional Domestic springs and Sport Compact springs. Precision CNC-machined from aerospace quality titanium, these Pro Retainers are fully heat-treated and finished to exact tolerances, adding strength while offering a 40% weight reduction over conventional steel retainers. Examine the overall quality of Ferrea’s Pro-Series Retainers and see why professional engine builders demand Ferrea Racing Components.


- Valve Stem Size: 5 mm
- Diameter (A): 20.32 mm
- Inn Step Diameter (C): 15.74 mm


References: INTAKE Single Spring-7 Degree Pro CNC Ferrea Racing Springs #S10158. Use Factory OEM Valve Locks.

Replaces OEM Part #   11-34-7-539-917 / 11 34 7 539 917 / 11347539917