Edelbrock VRS-4150 Race & Performance Carburetor #1308-E85 has features that benefit both racers and high-performance street enthusiasts. Custom metering blocks and extra-large fuel jets specifically built for E-85 applications. Annular boosters provide superior air-fuel mixing for exceptional performance. The 20% larger fuel bowls use ribs to minimize incoming fuel foaming and control slosh. Nitrophyl floats shaped to avoid shutting off fuel flow during hard cornering. Jet extenders in the secondary bowl keep the jets covered in fuel under hard acceleration. Dual 50cc accelerator pump circuits can satisfy large engine sizes. The one-piece 3.75-inch-tall aluminum body is a direct fit on either 4150 or 4500-style intake manifolds. The throttle arm includes all the popular transmission kickdown take-off points. Vacuum ports for PCV, power brake, vacuum advance, and transmission modulator for a direct bolt-on installation. Built-in provision for a GM three-wire TPS. Four-circuit billet metering blocks use industry standard-size screw-in bleeds and jets. The intermediate fuel circuit provides extra fuel just after the blade passes the transfer slot for incredible throttle response. Air bleeds on top of the carburetor provide a quick way to fine-tune each fuel circuit. The high-speed fuel circuit has two air bleed paths – one for lower and one for upper sections of the main well for greater fuel ratio control at high RPM. Two auxiliary idle air screws allow users to change idle speed without moving the parked throttle blades away from their ideal position. The idle circuit features interchangeable jets and four mixture screws to create a smooth, clean idle, even with the biggest camshafts. Dual power valves allow leaner cruise and add fuel as you get deeper into the throttle for great street performance driving. Protection circuits prevent backfires from damaging the diaphragms.