The SpeedFactory HD Detent Spring Kit fits all hydraulic DOHC B-Series (B16, B18, B20), cable (YS1 only), all K-Series, ONLY D16Y, D17A, F20B, F22A/B, H22A, and H23 transmissions. We have been using these springs in our own transmission builds for years, and now you can too ! Add enjoyment to your driving experience with this simple to install and inexpensive upgrade that gives improved feel and shift action as you engage each gear. The SpeedFactory HD Detent Spring Kit is a set of upgraded coil springs that increases the positive ratcheting feel of your transmission, with an over 80% increase in spring rate over the soft factory springs. These spring kits are suitable for use in any car, street or track and are ideal for anyone desiring improved shifting feel. Greatly improved tactile feedback/feel of each shift also helps ensure that the fork is fully in the desired gear position, and that it stays there. Simple installation takes just minutes in the car: 1) Remove the OEM Spring Setting Bolts one at a time, taking care not to lose the OEM spring or ball. 2) Install the OEM ball, SpeedFactory HD Spring, and the OEM Spring Setting Bolt. 3) Torque Spring Setting Bolt to proper OEM specification (16 ft.- lb.) 4) Repeat this procedure to upgrade all detent springs in your transmission. 5) Enjoy crisper, more defined shifting!