Dual valve spring kit

For the most extreme Miata engine. If you're building a track car, are planning on extended run time above 7500 rpm or boost 18 psi or more - they're what you need.

Aluminum spring seat, chrome silicon steel springs and titanium retainer. Sold in sets of 16 for a complete head. Fits all NA and NB Miatas. NA valves will require the use of valve keepers from a NB engine (not included).

Head Diam Pressure (lbs@mm) Max lift Coil Bind Rate O.D. (mm) I.D. (mm) Seat Open (lift) mm mm lbs./mm 1994-05 27.50 15.20 74 @ 34.2 177 @ 10.5 11.50 20.70 12.1