Product Summary

Long Block Crate Engine Type, 9.1:1 Compression Ratio

  • Oil: Conventional / Non Synthetic 10W30
  • Oil Filter: Wix or K&N
  • Timing: 34-36 Degrees
  • Spark Plug Gap: .035”
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Key Specs

Crate Engine TypeLong Block
Compression Ratio9.1:1
Engine Displacement360 cu. in.
Camshaft TypeHydraulic Roller
Cylinder Head MaterialCast Iron
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Need To Know

Made to Order

This custom item will ship when completed

Truck Shipment

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ATK Engines HP73 Details

Engine Specifications:

  • HP: 320
  • TQ: 410
  • Block: OE Magnum roller block 1993-2001
  • Bore/Stroke: up to 4.060” x 3.580”
  • Displacement: 360CI
  • Crankshaft: OE Cast
  • Rods: OE 6.123”
  • Pistons: Hypereutectic 9:1 compression
  • Rings: Moly
  • Camshaft: Hyd. roller
  • Cam Specs: OE Magnum grind
  • Timing Chain: Double roller
  • Cylinder Heads: OE Magnum cast iron 65cc 1.78/1.50
  • Rocker Arms: Steel 1.6 Pedestal Rockers• Oil Pan: OE front sump 5qt
  • Oil Pump: Melling STD volume (does not come with an oil pump driveshaft)

    Engine Info:

  • Flexplate/Flywheel: Internally balanced – Pioneer #FRA-478 (requires Ext. balanced converter)
  • Balancer: Externally balanced
  • Intake Manifold: Edelbrock performer RPM air gap dual plane #7577
  • Distributor: Pro billet RTR (Iron Gear)
  • Water Pump: OE early pump
  • Carburetor: Quick Fuel 680CFM vacuum secondary’s electric choke #HR-680
  • Fuel Pump: Holley mechanical 110GPH #12-360-11
  • Spark Plugs: Autolite #3923
  • Spark Plug Wires: 8mm
  • Oil: Conventional / Non synthetic 10W30
  • Oil Filter: Wix or K and N
  • Timing: 34-36 Degrees
  • Spark Plug Gap: .035”
  • Firing Order: 18436572
  • Octane: 89+
  • Stall Converter: Stock
  • Exhaust: 1 5/8 Headers

    Notes: If using a neutral balance converter, you need to use an externally balanced magnum 360 flex plate. Valve covers are now the Edelbrock version of this same valve cover (Black Finned).

    Disclaimer: The parts listed are ATK’s recommendations of parts to be used to obtain our power figures listed. Power figures can vary based on parts used by the end user. It is the customer’s responsibility to verify components will work in their application. Some modifications to the vehicle may be required using these and or other aftermarket parts. . ATK reserves the right to substitute parts used in engines if necessary.

  • CARB Warning

    Follow EPA, CARB, and state regulations for engine changes

    Emissions warning: this part is for vehicle engine changes, not direct oem engine replacements. In California, engine changes are legal when done in compliance with California bureau of automotive repairs (bar) engine change policy. For assistance, call bar referee at: (800) 622-7733. And see https://bar.Ca.Gov/consumer/smog_check_program/engine_changes. All customers must comply with federal epa mobile source enforcement memorandum no. 1a (and addendum) and all applicable state regulations when conducting engine changes. Improper installation and/or use of this part in California may subject the installer and/or owner to a $37,500 penalty per violation per vehicle, revocation of registration, loss of use on California public right of ways, and proof of correction for tampering. There are similar restrictions and penalties under federal law and laws of all states for use of this engine change part on makes or models of vehicles that render them noncompliant with applicable state and/or federal emission laws with penalties under federal law of up to approximately $45,268 per tampered vehicle and/or engine

    ATK Engines HP73 Specifications

    KEY SPECS
    MFG. Part #HP73
    BrandATK Engines
    Crate Engine TypeLong Block
    Compression Ratio9.1:1
    Engine Displacement360 cu. in.
    Camshaft TypeHydraulic Roller
    Cylinder Head MaterialCast Iron
    Piston MaterialHypereutectic Aluminum
    Carburetor IncludedNo
    Intake Manifold IncludedNo
    Distributor IncludedNo
    Valve Covers IncludedYes
    Cylinder Heads IncludedYes
    Throttle Body IncludedNo
    Timing Cover IncludedYes
    Oil Pan IncludedYes
    Water Pump IncludedYes
    Harmonic Balancer IncludedNo
    Flexplate IncludedNo
    Flywheel IncludedNo
    Air Cleaner IncludedNo
    Spark Plugs IncludedNo
    Spark Plug Wires IncludedNo
    Computer IncludedNo
    Wiring Harness IncludedNo
    GENERAL
    Material TypeCast Iron
    GTIN Code00653517546983
    Sold in QuantityEach

    Questions & Answers

    Fitment

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