ATK HP46M-MAG Mopar 408 Magnum 465HP Stage 2 Mid-Dress Crate Engine

Description

Seeking brutal small-block Mopar power? Select the ATK HP46M-MAG Crate Engine in Stage 2 mid-dress configuration. Producing 465 horsepower at 5,500 RPM and 500 lb-ft torque at 4,400 RPM, this 408 cubic inch Magnum stroker comes with an aluminum intake and water pump, giving builders full freedom to select their preferred fuel induction.

Engine architecture centers on a heavy-duty 5.9L 360 Magnum cast iron block clearanced for high-stroke rotating counterweights. The bottom end contains an internally balanced 4340 forged steel 4.000-inch crankshaft, 6.123-inch forged 4340 H-beam rods, and 10.0:1 forged pistons inside 4.030-inch bores. A 5-quart center-sump steel oil pan ensures steady lubrication reserves under severe lateral vehicle acceleration.

Key Features of ATK HP46M-MAG

Classic Mopar fans buy ATK HP46M-MAG crate engine packages to drop modern Magnum stroker power into vintage engine compartments while retaining personal induction components. This mid-dress unit powers classic Dodge Barracudas, D150 pickups, and restomod muscle cars.

• Single-plane aluminum intake manifold comes torqued in place to eliminate intake runner vacuum leaks under heavy load.
• Aluminum cylinder heads drop total front-end vehicle weight while promoting accelerated heat rejection under high engine loads.
• 2.02-inch intake and 1.60-inch exhaust valves flow dense air charges straight to high-displacement combustion chambers.
• 0.540-inch lift hydraulic roller camshaft profiles maximize valve lift for sudden acceleration off standing launches.
• 230-degree intake duration at 0.050-inch lift ensures a wide powerband spanning from 2,500 up to 6,000 RPM.
• 1.6:1 ratio aluminum roller rockers minimize pushrod resistance and stop valve guide friction under continuous load.
• ATK HP46M-MAG mid-dress models arrive with a cast iron water pump featuring factory Mopar belt alignment.
• Precision internally balanced crank train avoids cumbersome weighted external balance flywheels or flexplates.

Dyno Certification Output Band

Dynamometer testing confirms 465 brake horsepower at 5,500 RPM alongside a broad 500 lb-ft torque curve peaking at 4,400 RPM. The engine maintains steady 13 in-Hg manifold idle vacuum to actuate street car power brake servos without reserve canisters. Engineered for 91-octane service station gasoline, the lubrication system sustains 45 to 65 PSI oil pressure during sustained road operations.

Bay Packaging Transmission Drop

External envelope dimensions mirror standard Chrysler small-block blocks, ensuring drop-in placement between vintage Mopar frame rails. The rear crank flange requires a neutral-balance flexplate or flywheel to mate with automatic or manual transmissions. Motor mount points accept factory conversion brackets without header primary tube or steering shaft interference.

Pre-Run Setup Misuse Prohibitions

Prior to turning the ignition switch, pressure-feed the lubrication passages using an intermediate shaft primer tool to wet the crank bearings. Fill the crankcase with 10W-30 mineral break-in oil fortified with zinc additives. This power unit is not built for boat marine drives, continuous forced-induction boost beyond 6 PSI, or unmetered nitrous systems.

• Drain the break-in lubricant and mount a fresh spin-on oil filter after completing the first 500 street miles.
• Inspect intake manifold hold-down fasteners and water pump gaskets every 3,000 miles during routine vehicle service.
• Examine external oil pan bolts and inspect cooling system integrity every 12 months or 12,000 highway miles.

Warranty Statement Physical Contents

ATK backs this performance engine with a 24-Month or 50,000-Mile street warranty covering materials and craftsmanship. The secure crate contains the long block, aluminum intake manifold, cast iron water pump, timing pointer, oil pan, harmonic balancer, valve covers, and official dynamometer verification sheet.