{"product_id":"atk-5-7l-hemi-crate-engine-400hp-gen-iii-hemi-long-block-hp103t","title":"ATK 5.7L HEMI Crate Engine 400HP | Gen III HEMI Long Block | HP103T","description":"\u003ch2\u003e\u003cstrong\u003eATK High Performance Chrysler 5.7L Gen III HEMI Crate Engine – 400 HP | HP103T\u003c\/strong\u003e\u003c\/h2\u003e \u003cp class=\"ds-markdown-paragraph\"\u003eUnlock the legendary power of a modern HEMI for your project. The ATK HP103T is a high-performance, remanufactured 5.7L Gen III HEMI long block crate engine built to deliver over 400 horsepower, offering an exceptional balance of street performance, reliability, and value. This engine is the ideal foundation for anyone looking to upgrade a modern Mopar vehicle or inject classic muscle cars, trucks, and Jeeps with state-of-the-art power.\u003c\/p\u003e \u003cp class=\"ds-markdown-paragraph\"\u003eCollaboratively engineered with Comp Cams, this HEMI is equipped with a performance hydraulic roller camshaft and eliminates the complex Multi-Displacement System (MDS), simplifying swaps and enhancing durability for performance applications. The build features key upgrades including billet full roller rockers, hypereutectic pistons, and a reconditioned valvetrain, all precision-assembled to ensure robust power delivery.\u003c\/p\u003e \u003cp class=\"ds-markdown-paragraph\"\u003eSold as a complete long block, the HP103T provides the flexibility to customize your intake, exhaust, and accessory drive to perfectly suit your vehicle’s needs. Whether you’re modernizing a classic Mopar, boosting your Ram 1500, or executing a groundbreaking Jeep swap, this ATK HEMI provides a turn-key engine core that’s dyno-ready and built to perform.\u003c\/p\u003e \u003ch3\u003e\u003cstrong\u003eTechnical Specifications\u003c\/strong\u003e\u003c\/h3\u003e \u003cdiv class=\"ds-scroll-area _1210dd7\"\u003e \u003cdiv class=\"ds-scroll-area__gutters\"\u003e \u003cdiv class=\"ds-scroll-area__horizontal-gutter\"\u003e\u003c\/div\u003e \u003cdiv class=\"ds-scroll-area__vertical-gutter\"\u003e\u003c\/div\u003e \u003c\/div\u003e \u003ctable\u003e \u003cthead\u003e \u003ctr\u003e \u003cth\u003eSpecification Category\u003c\/th\u003e \u003cth\u003eDetail\u003c\/th\u003e \u003c\/tr\u003e \u003c\/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eHP103T\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eEngine Type\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eChrysler Gen III HEMI\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eDisplacement\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e5.7L \/ 345 cu. in.\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eMax Horsepower (HP)\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e400+ HP (Estimated)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eCompression Ratio\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e9.6:1\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eEngine Block\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eRemanufactured OEM Cast Iron Block\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eCrankshaft\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eOEM Reground \u0026amp; Micro-Polished\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eConnecting Rods\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eOEM Reconditioned\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003ePistons\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eHypereutectic with Chromoly Rings\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eCylinder Head Material\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eAluminum\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eValvetrain\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eBillet Full Roller Rockers, Upgraded Pushrods \u0026amp; Springs\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eCamshaft Type\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eHydraulic Roller (Non-MDS)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eBalance\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eInternal\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eAssembly Level\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eLong Block\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003c\/div\u003e \u003ch3\u003e\u003cstrong\u003eWhat’s Included (Long Block)\u003c\/strong\u003e\u003c\/h3\u003e \u003cdiv class=\"ds-scroll-area _1210dd7\"\u003e \u003cdiv class=\"ds-scroll-area__gutters\"\u003e \u003cdiv class=\"ds-scroll-area__horizontal-gutter\"\u003e\u003c\/div\u003e \u003cdiv class=\"ds-scroll-area__vertical-gutter\"\u003e\u003c\/div\u003e \u003c\/div\u003e \u003ctable\u003e \u003cthead\u003e \u003ctr\u003e \u003cth\u003eIncluded\u003c\/th\u003e \u003cth\u003eNot Included \/ Required Separately\u003c\/th\u003e \u003c\/tr\u003e \u003c\/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd\u003e✓ Remanufactured \u0026amp; Assembled Short Block\u003c\/td\u003e \u003ctd\u003e✗ Intake Manifold\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e✓ Aluminum Cylinder Heads w\/ Roller Rockers\u003c\/td\u003e \u003ctd\u003e✗ Oil Pan, Pickup Tube, \u0026amp; Timing Cover\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e✓ Hydraulic Roller Camshaft (Non-MDS)\u003c\/td\u003e \u003ctd\u003e✗ Front Accessory Drive (Balancer, Water Pump)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e✓ Upgraded Valvetrain Components\u003c\/td\u003e \u003ctd\u003e✗ Flexplate \/ Flywheel\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e✓ Valve Covers (Note: May vary)\u003c\/td\u003e \u003ctd\u003e✗ Ignition System (ECU, Harness, Coils, Plugs)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003c\/td\u003e \u003ctd\u003e✗ Exhaust Manifolds \/ Headers\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003c\/div\u003e \u003ch3\u003e\u003cstrong\u003eComparison Table: ATK HP103T vs. Alternatives\u003c\/strong\u003e\u003c\/h3\u003e \u003cdiv class=\"ds-scroll-area _1210dd7\"\u003e \u003cdiv class=\"ds-scroll-area__gutters\"\u003e \u003cdiv class=\"ds-scroll-area__horizontal-gutter\"\u003e \u003cdiv class=\"ds-scroll-area__horizontal-bar\"\u003e\u003c\/div\u003e \u003c\/div\u003e \u003cdiv class=\"ds-scroll-area__vertical-gutter\"\u003e\u003c\/div\u003e \u003c\/div\u003e \u003ctable\u003e \u003cthead\u003e \u003ctr\u003e \u003cth\u003eFeature\u003c\/th\u003e \u003cth\u003eATK HP103T 5.7L HEMI\u003c\/th\u003e \u003cth\u003eOEM Stock 5.7L HEMI\u003c\/th\u003e \u003cth\u003eBluePrint 5.7L HEMI (New Build)\u003c\/th\u003e \u003c\/tr\u003e \u003c\/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003ePower Output\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e\u003cstrong\u003e400+ HP (Performance Cam, No MDS)\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e~350 HP (Includes MDS)\u003c\/td\u003e \u003ctd\u003eVaries (Often 350-400HP)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eKey Differentiator\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e\u003cstrong\u003ePerformance Cam \u0026amp; Valvetrain, No MDS\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eOEM Spec, Full MDS Functionality\u003c\/td\u003e \u003ctd\u003eAll-New Components\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eBlock Core\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e\u003cstrong\u003eRemanufactured OEM Casting\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eNew or Remanufactured OEM\u003c\/td\u003e \u003ctd\u003eNew Aftermarket Casting\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eIdeal For\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e\u003cstrong\u003eSwaps, Restomods, Performance Upgrades\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eDirect OEM Replacement\u003c\/td\u003e \u003ctd\u003eRestomods, New Builds\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eComplexity\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e\u003cstrong\u003eSimplified (MDS Deleted)\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eComplex (MDS Active)\u003c\/td\u003e \u003ctd\u003eSimplified (Typically No MDS)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eValue Proposition\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e\u003cstrong\u003eHigh Performance on an OEM Core\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eOEM Reliability \u0026amp; Emissions Compliance\u003c\/td\u003e \u003ctd\u003eNew Component Warranty \u0026amp; Precision\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003c\/div\u003e \u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions (FAQs)\u003c\/strong\u003e\u003c\/h3\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003eQ1: What does “Non-MDS” mean and why is it beneficial?\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eA:\u003c\/strong\u003e MDS (Multiple Displacement System) is Chrysler’s cylinder deactivation technology. It uses specialized lifters and a complex control system to switch between 4 and 8 cylinders. The ATK HP103T \u003cstrong\u003edeletes this system\u003c\/strong\u003e by using a standard hydraulic roller cam and non-MDS lifters. This simplifies the engine, eliminates a potential failure point, and makes it vastly easier to wire and tune for engine swaps, as it doesn’t require the OEM body control modules.\u003c\/p\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003eQ2: Will this engine work in my Jeep Wrangler TJ\/JK or classic car swap?\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eA: Yes, it is an excellent candidate.\u003c\/strong\u003e The removal of MDS makes it one of the most popular choices for swaps. You will need a complete HEMI swap kit that includes custom engine mounts, headers, an oil pan designed for your chassis, and a standalone wiring harness and ECU (like from Hotwire Auto or similar) to make it run.\u003c\/p\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003eQ3: Is this a complete, ready-to-run engine?\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eA: No.\u003c\/strong\u003e This is a \u003cstrong\u003elong block\u003c\/strong\u003e. It includes the engine block, cylinder heads, camshaft, and internal components. You must source and install all external components: intake manifold, throttle body, oil pan, front accessories, ignition system (coils, plugs, wires), and engine management (ECU and harness).\u003c\/p\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003eQ4: Can I use my stock intake, exhaust, and accessories from my Ram 1500?\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eA:\u003c\/strong\u003e For a direct replacement in a vehicle that originally had a 5.7L HEMI, yes, your stock accessories, intake, and exhaust manifolds will physically bolt on. However, \u003cstrong\u003ethe performance cam will require a custom tune\u003c\/strong\u003e for the engine to run correctly, even with all the stock components.\u003c\/p\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003eQ5: What kind of warranty does this engine have?\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eA:\u003c\/strong\u003e ATK Engines typically come with a robust limited warranty. Please confirm the specific terms with your authorized dealer at the time of purchase, but industry standard is often 3 years\/unlimited miles for remanufactured performance engines.\u003c\/p\u003e \u003ch3\u003e\u003cstrong\u003ePros and Cons\u003c\/strong\u003e\u003c\/h3\u003e \u003cdiv class=\"ds-scroll-area _1210dd7\"\u003e \u003cdiv class=\"ds-scroll-area__gutters\"\u003e \u003cdiv class=\"ds-scroll-area__horizontal-gutter\"\u003e \u003cdiv class=\"ds-scroll-area__horizontal-bar\"\u003e\u003c\/div\u003e \u003c\/div\u003e \u003cdiv class=\"ds-scroll-area__vertical-gutter\"\u003e\u003c\/div\u003e \u003c\/div\u003e \u003ctable\u003e \u003cthead\u003e \u003ctr\u003e \u003cth\u003ePros\u003c\/th\u003e \u003cth\u003eCons\u003c\/th\u003e \u003c\/tr\u003e \u003c\/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd\u003e\n\u003cstrong\u003eSignificant Power Gain:\u003c\/strong\u003e 400+ HP output overrules stock HEMI models.\u003c\/td\u003e \u003ctd\u003e\n\u003cstrong\u003eLong Block Only:\u003c\/strong\u003e Requires significant additional parts investment for a complete running engine.\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\n\u003cstrong\u003eSimplified for Swaps:\u003c\/strong\u003e Elimination of MDS drastically reduces wiring and tuning complexity.\u003c\/td\u003e \u003ctd\u003e\n\u003cstrong\u003eRemanufactured Core:\u003c\/strong\u003e Built on a used OEM block, not a brand-new casting.\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\n\u003cstrong\u003ePerformance Upgrades Included:\u003c\/strong\u003e Features Comp Cams camshaft and roller rockers out of the box.\u003c\/td\u003e \u003ctd\u003e\n\u003cstrong\u003eRequires Custom Tuning:\u003c\/strong\u003e Will not run properly with a stock ECU calibration.\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\n\u003cstrong\u003eProven HEMI Architecture:\u003c\/strong\u003e Leverages the renowned reliability and torque of the 5.7L HEMI design.\u003c\/td\u003e \u003ctd\u003e\n\u003cstrong\u003eNot Emissions Legal:\u003c\/strong\u003e For off-road\/racing use only due to changes in cam and deletion of emissions equipment (MDS).\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\n\u003cstrong\u003eExcellent Value:\u003c\/strong\u003e Offers a high-horsepower starting point for a fraction of the cost of a full custom build.\u003c\/td\u003e \u003ctd\u003e\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003c\/div\u003e \u003ch3\u003e\u003cstrong\u003eConclusion \u0026amp; Ideal Use Case\u003c\/strong\u003e\u003c\/h3\u003e \u003cp class=\"ds-markdown-paragraph\"\u003eThe ATK HP103T 5.7L HEMI is the ultimate power plant for the enthusiast who wants modern Mopar performance without modern electronic complexities. It is engineered for those who prioritize power and simplicity for a project build.\u003c\/p\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003eThis engine is perfectly suited for:\u003c\/strong\u003e\u003c\/p\u003e \u003cul\u003e \u003cli\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003eClassic Mopar Restomods\u003c\/strong\u003e (Charger, Challenger, Cuda)\u003c\/p\u003e \u003c\/li\u003e \u003cli\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003eJeep Wrangler \u0026amp; Grand Cherokee HEMI Swaps\u003c\/strong\u003e\u003c\/p\u003e \u003c\/li\u003e \u003cli\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003ePerformance Upgrades\u003c\/strong\u003e for 2003-2008 Ram 1500s, Durangos, and other non-MDS vehicles\u003c\/p\u003e \u003c\/li\u003e \u003cli\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003eCustom Hot Rods and Kit Cars\u003c\/strong\u003e needing a reliable, torque-rich V8\u003c\/p\u003e \u003c\/li\u003e \u003cli\u003e \u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003eAnyone looking for a simplified, high-output Gen III HEMI foundation.\u003c\/strong\u003e\u003c\/p\u003e \u003c\/li\u003e \u003c\/ul\u003e \u003cp class=\"ds-markdown-paragraph\"\u003eIf your goal is a straightforward, powerful, and tuner-friendly HEMI swap that captures the modern muscle spirit, the ATK HP103T is a formidable and smart choice.\u003c\/p\u003e","brand":"USA AUTO PARTS","offers":[{"title":"Default Title","offer_id":53342615798060,"sku":null,"price":3032.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0973\/9246\/0076\/files\/9d4367e3-DD-3.jpg?v=1781740795","url":"https:\/\/usaautoparts.net\/products\/atk-5-7l-hemi-crate-engine-400hp-gen-iii-hemi-long-block-hp103t","provider":"USA AUTO PARTS","version":"1.0","type":"link"}