Adjustable billet coil over shock throttle return spring kit for a Holley Dominator carburetor. Our kits are the ONLY ones on the market that use the spring in compression. By putting the spring in compression and then capturing it on the shock it means that even if the spring were to break because its captured it cant fall off and fail...a HUGE step forward in safety!! Once this kit is installed, it allows the user to adjust the tension in the throttle return spring without having to change the actual spring. Simply spin the adjuster ring on the threaded shock body to add or remove preload on the shock in the same way you would on the coil over of your suspension. This allows you to change the way the throttle pedal feels without having to change the spring itself! All the bracketry is made of 6061 billet aluminum and is available in either a clear or black anodized finish. The shocks are also billet aluminum and can be ordered in 5 colors: clear, black, red, blue or purple.