The Edelbrock part # 35873 Pro-Flo 4 XT Sequential Port EFI System for Big-Block Chevy Rectangle Port engines has the latest in technology and features. The EFI system comes complete with a black finish Pro-Flo XT intake manifold and 35 Lb/Hr injectors capable of 550 HP with 58 p.s.i. fuel pressure. Also included is a plug and play single connection distributor designed to work specifically with Pro-Flo 4 and a made in the USA fully terminated high-quality harness with clearly labeled connections for a hassle-free installation. The new Pro-Flo 4 EFI systems feature an all-new ECU with a faster processor, a water proof design and is half the depth of the previous ECU. It also has an upgraded Bluetooth chip that is faster, more reliable and will not drop connection. We've added more features for the advanced tuner giving you control over air-fuel ratios, ignition curve, idle speed, acceleration fuel, coolant fans, Rev limiter while retaining the simplicity Pro-Flo is known for. The key to the system is our exclusive E-Tuner 4 app with dyno developed base calibrations. The E-Tuner 4 app uses a Bluetooth wireless connection to communicate with the ECU's self-learning capability to continually adjust the calibration to get maximum performance. E-Tuner 4 features a simple and easy to use setup wizard to help you get started. Best of all, the E-Tuner 4 app is free and can be downloaded from the Google Play Store, allowing you to use an Android based smart phone or tablet. If you don't have a compatible device, then we also offer kits that include a 7" Android tablet with the E-Tuner 4 app pre-installed. Multiple dash displays are included to allow you to monitor engine vitals from an Android smart phone or tablet. Pro-Flo 4 does not require laptop tuning.