One of the best, and sometimes missed tuning tricks is not to just optimize your initial timing, but to bring in timing advance more quickly than the stock distributor can allow. Bringing timing more quickly than stock can provide substantial increases in both torque and horsepower depending on your combination.This is done by changing the springs under the cap. This kit includes three sets of springs which can be used in different combinations to provide full advance sooner than stock. Use lighter springs to bring the advance more quickly, and heavier springs to bring it in more slowly. Two new weights with nylon bushings are also included as are instructions to help with installation. Springs are color code as follows: Light Springs - Black Medium Springs - Silver Heavy Springs - Gold