An absolute must for anyone wishing to stretch the powerband of their 30v engine out past 7500 rpm or so safely. These take a two pronged approach by increasing the spring rates meanwhile reducing the mass of the retainer, by using titanium. The use of titanium provides an adequate fatigue life to be acceptable for all but the highest mileage street use. These will allow usage up to 8000 rpm although we have used them for occasional use to 8500rpm on hydraulic lifters.
This is for a complete set of 30 springs and retainers.
This Part Fits the Following Vehicles