The Holley LS3 Lo-Ram intake manifold kits are designed for GM LS Gen III and IV engines equipped with GM LS3/L92 cylinder heads. These intake manifolds will work with OE or aftermarket cylinder heads. The Ultra Lo-Ram intake manifolds are designed for forced induction (supercharged or turbocharged) engine applications with peak power at 7000-8000 rpm depending on the application. The Ultra Lo-Ram plenum flange has a 105 mm opening to work with throttle body part number 112-581 or similar models. The base intake manifold is designed with a lower overall height to fit under a stock or mildly modified hood in the front configuration. The LS3 Ultra Lo-Ram is constructed to provide a very low profile modular intake manifold suitable for fabrication of special throttle body adapters or inlet ducts for custom installations. Available with single or dual injector provisions and a burst panel flange options.The fuel rail kits come with two sets of brackets. A set for long (usually standard length) fuel injectors and a set for short (such as Pico, or LS7) fuel injectors.