Holley Universal Multi-Point Main Harness 558-210 | An Injector Harness is required and Holley offers two. The harness with USCAR/Stock injector connectors will cover most applications that are using the factory injectors. The other harness is for the Bosch and Holley (or Jetronic/Minitimer) injector connector that is commonly used in aftermarket applications for larger injectors. View the image gallery to see images of both types of injectors.