Overview Reviews Product Description 558-104 Holley EFI Universal MPFI Main Harness Universal MPFI Main Harness for HP EFI & Dominator EFI Product Videos Custom Field Product Reviews Write a Review Write a Review × 558-104 Holley EFI Universal MPFI Main Harness Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *