Buy ATK High Performance Chrysler 360 Magnum 320 HP Stage Online
The ATK High Performance Chrysler 360 Magnum 320 HP Stage 1 long block crate engine delivers street-ready muscle, exceptional reliability, and broad-range torque for your Mopar project. Designed as a high-quality performance upgrade, this precision-built long block transforms your vehicle with 320 horsepower and smooth, reliable power delivery.
Hand-assembled using top-grade internal 360 magnum motor components, this engine package features a blueprinted OE Chrysler 360 block, hydraulic 360 magnum engine roller camshaft, quality aluminum/cast cylinder heads, and a heavy-duty rotating 5.9 magnum 408 stroker kit assembly. Engineered to balance crisp throttle response with dependable daily drivability, it serves as the 360 magnum motor ultimate drop-in core for restorations, street rods, and truck builds.
By delivering true turn-key potential in a Stage 1 configuration, this motor allows you to reuse or select your preferred external induction, ignition, and fuel delivery 360 chrysler engine systems while providing a rock-solid, high-output foundation. Upgrade your vehicle with the strength, durability, and classic Mopar punch of the ATK High Performance Chrysler 360 Magnum 320 HP Stage 1 engine.
Product Specifications
| Specification | Details |
| Engine Series | ATK High Performance Chrysler 360 Magnum |
| Part Number | HP73 |
| Engine Stage | Stage 1 Long Block |
| Horsepower Rating | 320 HP |
| Torque Rating | ~410 lb-ft |
| Displacement | 360 cu. in. (5.9L) |
| Engine Block | OE Chrysler 360 Small Block (Hand-selected & Precision Machined) |
| Bore x Stroke | 4.000 in. x 3.580 in. (Standard) |
| Crankshaft | Cast Steel OEM Spec |
| Connecting Rods | Heavy-Duty Forged Powdered Metal / Steel |
| Piston Type | Hypereutectic Aluminum |
| Compression Ratio | ~9.1:1 – 9.5:1 (Optimized for pump gas) |
| Camshaft Style | Hydraulic Roller |
| Cylinder Heads | OE Cast Iron High-Flow Magnum Heads |
| Valve Train | Stamped Steel Rocker Arms with Hardened Pushrods |
| Recommended Fuel | 87 to 91 Octane Pump Gasoline |
Key Benefits
-
Turnkey Power Upgrade: Delivers a reliable 320 HP boost over factory stock engines, ideal for daily drivers, street rods, and truck restorations without sacrificing driveability.
-
Pump-Gas Friendly: Engineered with an optimized compression ratio that runs smoothly on standard 87 to 91 octane pump gas—no costly racing fuels or Octane boosters needed.
-
Precision Machining & Quality Assembly: Dynamically balanced rotating assembly and blueprinted tolerances ensure minimum internal friction, quieter operation, and extended engine life.
-
Modern Hydraulic Roller Setup: Eliminates flat-tappet camshaft wear issues and reduces internal friction, delivering faster throttle response and improved efficiency across the RPM band.
-
Flexible Customization (Stage 1 Configuration): Provides a solid, fully built core while giving you full control to match your choice of intake manifold, ignition system, carburetor, or EFI setup.
-
Drop-In Mopar Compatibility: Designed as a direct bolt-in solution for Chrysler, Dodge, and Plymouth applications using small-block Mopar mounting points.
What components are included with the ATK High Performance Chrysler 360 Magnum 320 HP Stage 1 long block?
The ATK High Performance Chrysler 360 Magnum 320 HP Stage 1 engine includes the remanufactured/blueprinted engine block, crankshaft, connecting rods, pistons, hydraulic roller camshaft, timing set, cylinder heads, and valve train assembly. As a Stage 1 long block, external accessories such as the intake manifold, carburetor/EFI, distributor, water pump, and oil pan accessories must be re-used or purchased separately.
What fuel octane level is required to run this engine safely?
Because of its optimized compression ratio and street performance tuning, the ATK High Performance Chrysler 360 Magnum 320 HP Stage 1 crate engine is dyno-tested and engineered to run reliably on standard 87 to 91-octane pump gasoline without requiring race fuel or special additive boosters.

Reviews
There are no reviews yet.