Overview Reviews Product Description 558-108 Holley EFI Ford 2V & 4V Modular Main Harness Main harness for 99-04 2 & 4 Valve Ford Modular (4.6 & 5.4L) Engines. Product Videos Custom Field Product Reviews Write a Review Write a Review × 558-108 Holley EFI Ford 2V & 4V Modular Main Harness Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *