You're almost there. The end of a tough race is fast approaching, but to win, you'll need to push your engine to the limit. The tach will read close to 9000 RPM. Such sustained red-line abuse is like sudden death overtime for your valve train. Ordinary roller valve springs will quickly succumb to resonant vibration, putting you out of the race. Only one valve spring can go there and come back alive, every time! Introducing Isky's new RAD-9000 process option for Tool Room valve springs. Under trade secret Radial-Densification (RAD), the physical properties of Tool Room springs are optimized for even greater surface to core uniformity. To insure they'll withstand the tortures of sustained high rpm operation, we subject each batch to the most rigorous real world test standard ever created, SPINTRON-TEST II. It's a no holds barred run as high as 9000 RPM where for over 1, 000 miles, race ending competitive abuse is continuously revisited. This pass or fail benchmark is the only test of its kind in the performance industry and every set of Tool Room springs conforms to its high standard. So why take a chance on anything else? Run the only racing valve springs with sustained red-line protection. RAD-9000 process Tool Room valve springs from Isky. Absolutely the world's finest, and the new standard of excellence in endurance racing today! Full-Spectrum Harmonic Vibration Control: technologically advanced designs suppress surge and avoid harmonic convergence. 100% "Hands-On" Precision Manufactured by master valve spring craftsmen. Our standards are the highest in the performance industry! Absolute Maximum Endurance: Exclusive trade-secret endurance processing delivers "near zero" pressure drop after 1, 000 racing test miles! The 1, 000 Racing Mile Endurance Test Standard: Each set is guaranteed "race ready" because we test-prove every part number, every batch! Gold Stripe Test Certification: Tool Room springs earn their "Gold Stripes" and written certification only after two full sets go the distance! Exclusive Performance Guarantee: If you are not completely satisfied that our 9900 Series Tool Room springs are the most durable, fatigue resistant valve springs you have ever tried, return them to Isky for a full refund! Only precision Tool Room valve springs with the exclusive "Gold Stripe" deliver this level of full throttle, indefatigable performance!Pit Stop USA offers Isky Cams Precision Tool Room™ Single Valve Springs W, Damper (16) - 1.260" O.D. - 360 lbs., "Rate - 1.100" Coil Bind - firstname.lastname@example.org" Seat Pressure - email@example.com" Open Pressure - .600" Max Lift 295-D at low everyday prices. Be sure to check out all of our products from Isky Cams including Isky Cams Isky Cams Precision Tool Room Valve Springs.