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Chevrolet Performance 454 C.I.D. HO 425 HP Engine Assemblies 12568774

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Engine Assembly, Crate Engine, Chevy, 454 HO, 425 hp, Cast Iron Rectangle Port Heads, Each

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Manufacturer's Part Number: 12568774
Part Type: Crate Engines
Summit Racing Part Number: NAL-12568774

Engine Assembly Style: Long block
Crate Engine Cylinder Head Material: Cast iron
Assembled: Yes
Engine Balance: External
Intake Manifold Included: Yes
Cylinder Heads Included: Yes
Carburetor Included: No
Throttle Body Included: No
Distributor Included: No
Oil Pan Included: Yes
Valve Covers Included: Yes
Timing Cover Included: Yes
Water Pump Included: Yes
Harmonic Balancer Included: Yes
Flexplate Included: Yes
Flywheel Included: No
Air Cleaner Included: No
Spark Plugs Included: No
Spark Plug Wires Included: No
Computer Included: No
Wiring Harness Included: No
Rear Main Seal Style: 1-piece
Quantity: Sold individually.
Notes: This engine is not designed, nor intended to be used in any marine applications. Designed for pre-1976 street vehicles or any off-road vehicle. Engines installed in vehicles registered and normally operated outside of the United States carry no warranty. Clutch linkage bosses are drilled and tapped, plus includes a provision for a mechanical fuel pump.
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The 454 HO offers tremendous value in a big block crate engine. Based on the Gen VI 4-bolt mains with 1-piece rear main seal blocks with approximately 8.75:1 compression, 425 hp at 5,250 rpm and 500 ft./lbs. of torque at 3,250 rpm. The "HO" stands for High Output, which means you get Forged steel externally balanced crankshafts, forged steel LS6/LS7 "Dimple" rods, shot peened and magna fluxed with 7/16 in. rod bolts. Forged aluminum pistons, hydraulic roller camshafts with .510 in. intake lift, .540 in. exhaust lift and duration at .050 in. for intake is 211 and 230 for exhaust, lobe centerline is 112 degrees. Cast iron cylinder heads with rectangular port 118cc combustion chambers, 325cc intake runner volume with 2.19 in. intake valves and 1.88 in. exhaust. These heads are configured for 3/8 in. thread 7/16 in. shank rocker arm studs. Stamped steel self-aligning 1.7:1 ratio rocker arms come installed along with AC Delco spark plugs. Also included with these crate engines; oil pans, black powder coated aluminum valve covers, black powder coated aluminum timing covers, long style cast iron "V" belt rotation water pumps, 8 in. harmonic balancers, and 14 in. automatic flex plates.


Some parts are not legal for sale or use in California on any pollution-controlled motor vehicles

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