The patent pending GEN 3 main“body is 5/16 taller than the previous generation! This new height allowed for larger radius air entries which were optimized using Computational Fluid Dynamics (CFD) software to deliver smoother flow into new fully machined, big bore venturii. The main-body also features an integrated idle bypass valve that allows for idle adjustments while maintaining the correct throttle plate to transfer slot relationship as well as an extended air cleaner flange for easy air scoop attachment when using the available air scoop adapter. The Gen 3 utilizes high capacity fuel bowls which feature 20% more fuel capacity to eliminate starvation, integrated fuel shelf to minimize fuel aeration and internal baffling to control fuel slosh. Other features include all aluminum construction, 12-hole billet booster inserts, fully tunable billet metering blocks, adjustable external linkage, throttle position sensor mounting points and knurled (hand adjustable) curb idle screws. Each calibration has been dyno tested to deliver proven performance! Features:All aluminum construction saves 3.8lbs. over original models (28% weight savings) Gray anodized finish with black anodized billet aluminum metering block and booster inserts Designed for use on Marine high horsepower engines Fully machined from venturi throat to throttle bore for predictable & repeatable performance Integrated idle bypass valve allows for adjustment of idle while maintaining correct throttle plate to transfer slot relationship 12 hole billet booster inserts for superior atomization and crisp throttle response Metering blocks feature improved durability, true gasket sealing and fully adjustable (emulsion bleeds, power valve channel restrictors & idle feed restrictors) Dual 50cc accelerator pumps provide the perfect amount of fuel from idle to full throttle Fuel bowls provide 20% more fuel capacity while controlling slosh with internal baffling Clear sight windows on both sides of bowls for easy and safe fuel level adjustments Built in drain plug in front center of bowl provides easy access to empty contents of bowl 8 (o-ringed) inlet threads offer a large variety of plumbing options and can be plumbed from either side Factory ready TPS mounting points for use with data acquisition systems (Holley TPS P/N 534-214 available) Knurled (hand adjustable) primary and secondary curb idle screws allow for easy idle adjustment without the use of tools Contoured hex head squirter screws for streamlined airflow Fully adjustable stainless steel external linkage can be adjusted for 1:1 progressive, or soft progressive throttle activation. No linkage parts under the carburetor 100% wet-flow tested by Holley technicians to assure it arrives ready to run! J-Style vent tubes SPECS: Barrels: 4 Billet Color: Hard Core Gray with Black Booster: Annular Brand: Holley CFM: 1050 Choke: None Circuit: 3 Emission Code: 3 Finish: Hard Core Gray Fuel: Gasoline Fuel Inlet: Dual High Speed Air Bleed: 43 Idle Air Bleed Size: 65 Intermediate Air Bleed: 71 Marine Engine Size: Universal Material: Aluminum Model: 4500 Needle and Seat Size: 120;120 Primary Main Jet: 84 Primary Power Valve: 6.5 Primary Pump Nozzle Size: 35 Product Type: Carburetor Secondaries: Mechanical Secondary Main Jet: 84 Secondary Pump Nozzle Size: 35 Supercharged Application: No Throttle Bore: 2.000 inch Venturii Size: 1.690 inch Part Number: 0-80903HBM PitStopUSA.com Sells Holley 1050 CFM Gen 3 Marine Ultra Dominator Carburetor at low everyday prices. Be Sure to check out all of our products from Holley Performance including Holley Carburetors.