IN STOCK!

75% STIFFER ON THE BOTTOM END FOR AWESOME THROTTLE RESPONSE DOWN LOW BUT 15% SOFTER ON THE TOP END FOR FASTER SHIFT OUT ONCE THE RPM’S ARE UP FOR FASTER 0-60 TIMES AND PERFECT FOR BOOSTED APPLICATIONS AND LARGER TIRES.

BEST DESIGNED PRIMARY SPRING ON THE MARKET AND MADE IN THE USA BY HYPERCO FOR JBS.