The Hilborn EFI-R manifold systems combine Electronic Fuel Injection with the racing born performance and aggressive looks of Individual-Runner engine induction. Included with each kit is a universal Terminator X EFI system, providing cutting edge EFI technology. The Hilborn EFI-R systems are intended for the most serious naturally aspirated performance enthusiast. Each kit comes with a CAN-USB tuning dongle, allowing you to tune your EFI system specifically for your engine, via our free Terminator X EFI software. The engine valley covers are sold separate to allow the customer to choose the correct valley cover kit based on the engine deck-height, 300-802 - Std. 9.800-inch height or 300-803 - Tall 10.200-inch. This kit is designed to be used with the following Hilborn EFI-R intake manifolds: 300-800 for Big Block Chevrolet applications requiring 2-7/16-inch throttle bores 300-801 for Big Block Chevrolet applications requiring 2-5/8-inch throttle bores 300-807 for Big Block Chevrolet applications requiring 3-inch throttle bores