On some vehicles the MSD Crank Trigger Kit may require slight modifications to accommodate special engine plates, pulley systems, etc. This kit is designed to be used with the ATI Harmonic Balancer 917776 or 917215. Also compatible with Meziere water pump WP333 and LSX Blocks. Upgrading to an MSD Flying Magnet Crank Trigger Kit will deliver the precise and reliable signal that a high-performance engine requires. This kit gives you the ability to control timing electronically through a Holley EFI ECU (or other standalone engine management system/ignition controller). At the heart of the kit is the 3-wire Hall-Effect Sensor that is easier to set up, less susceptible to EMI/RFI interference/noise, and less likely to have false signals than other methods (Distributors and VR Magnetic Sensors). In addition, they are less prone to mechanical failure since there are no wear parts. With the included high-quality timing pointer and the use of a direct bolt-on, degreed balancer (ATI 917776 or 917215), you'll be able to adjust timing in the precise increments required for your LS Engine.