Introduction: Building a 550 HP HEMI MDS Delete Setup

For automotive enthusiasts, building a 550 horsepower HEMI engine with an MDS delete and Eagle forged internals is more than a project—it's a statement. Whether you're refreshing a tired 5.7L or 6.4L HEMI for a classic muscle car swap, or pushing a modern Dodge Challenger or Ram 1500 to its limits, understanding the financial commitment is critical. This article provides a comprehensive cost breakdown, explains why each component matters, and offers expert tips to avoid costly mistakes. By the end, you'll have a realistic budget and a clear build roadmap.

What Is MDS Delete and Why Do It?

Multi-Displacement System (MDS) is Chrysler's cylinder deactivation technology, designed to improve fuel economy by shutting down four cylinders under light load. While effective for daily driving, MDS can cause reliability issues in high-horsepower builds: the collapsing lifters are a common failure point, sending metal debris through the oil system. Deleting MDS means replacing the MDS lifters with standard non-MDS lifters, along with a compatible camshaft and valley cover. This eliminates a known weak link and allows you to run more aggressive cam profiles necessary for 550 hp.

Cost of MDS Delete Components

  • MDS Delete Lifter Set (non-MDS): $250–$400
  • MDS Delete Camshaft (non-MDS specific lobe arrangement): $350–$700 (often included in performance cam package)
  • MDS Delete Valley Cover: $150–$250
  • Pushrods (length-specific): $100–$200

Total MDS delete parts typically add $850–$1,550 to the build. Some aftermarket camshaft kits already include MDS-delete compatible parts, so factor this into the camshaft selection.

Why Eagle Forged Internals?

Eagle Specialty Products is a trusted name in performance rotating assemblies. Their forged pistons, rods, and crankshafts are engineered to withstand the extreme stresses of 550+ hp. Forged components offer superior fatigue strength compared to cast factory parts, which often crack under boosted or high-rpm conditions. While other brands like Manley or Callies are also excellent, Eagle offers a balance of quality and affordability—making them a popular choice for budget-conscious builds that still demand reliability.

Eagle Forged Internals Options for HEMI

  • Eagle Forged Pistons (custom or off-the-shelf, 2618 alloy): $650–$1,300
  • Eagle Forged Connecting Rods (4340 steel, H-beam): $750–$1,100
  • Eagle Forged Crankshaft (4340 steel, indexed and nitrided): $1,300–$1,900

You can also purchase a pre-assembled Eagle rotating assembly kit (pistons, rings, rods, bearings, crank) for around $2,800–$3,500, which often saves money over buying individually.

Detailed Cost Breakdown by Component

1. HEMI Engine Block

The block is the foundation. For 550 hp, a used production HEMI block (5.7L or 6.4L) can be cleaned and machined, but you must check for cracks and bore wear. A new Mopar crate block is pricier but guarantees no core issues.

  • New Mopar Crate Block (bare): $3,000–$5,500
  • Used/Remanufactured Block (after machining): $1,200–$2,500
  • Machine work (boring, honing, decking, line boring): $500–$1,200 (if using used block)

2. Performance Camshaft

A camshaft with around 230–240 degrees duration at .050 and 0.600–0.650 inch lift will help reach 550 hp on a naturally aspirated HEMI. Choose a cam designed for MDS delete, with non-MDS lobe profiles. Brand examples: Comp Cams, Brian Tooley Racing, or custom ground.

  • Performance Camshaft & Lifter Kit: $400–$900 (includes MDS delete lifters if spec'd)
  • Valve Springs & Retainers (for higher lift): $250–$450

3. High-Performance Cylinder Heads

Factory HEMI heads flow well, but ported aftermarket heads unlock 30–50 hp. For 550 hp, either port your factory heads or buy new castings from sources like EngineQuest or Brian Tooley Racing.

  • New Aftermarket Cylinder Heads (bare): $1,200–$2,200
  • Ported Factory Heads (labor + parts): $800–$1,500
  • Valve Train Upgrade (stainless valves, dual springs): $400–$700

4. Fuel System Upgrades

550 hp requires more fuel than a stock HEMI system can deliver. A bigger pump and injectors are mandatory, especially if you plan to use E85 later.

  • High-Flow Fuel Injectors (65–80 lb/hr for gas): $350–$700 (set of 8)
  • In-Tank Fuel Pump (Walbro 525 or similar): $200–$400
  • Fuel Pressure Regulator & Lines: $150–$350

5. Exhaust System

Free-flowing exhaust reduces backpressure and helps the engine breathe. For a HEMI swap, headers are essential; a full exhaust system may be needed depending on chassis.

  • Long Tube Headers (1-7/8 or 2 inch primary): $600–$1,200
  • Cat-Back Exhaust System (mandrel bent, 3 inch): $500–$1,100
  • Custom Y-Pipe or Exhaust Fabrication: $200–$500 (if not a kit)

6. Cooling & Oil System

High-horsepower engines generate extra heat. Upgrade the radiator, oil pan, and oil pump for reliability.

  • High-Performance Radiator (aluminum): $350–$700
  • High-Volume Oil Pump (Melling or similar): $150–$300
  • Oil Pan Baffle or Deep Sump Pan: $200–$500

7. ECU Tuning

Tuning is where all the parts come together. A custom tune on a chassis dyno or via a remote tuner is mandatory for safety and power. For HEMI engines, platforms like HPTuners or DiabloSport are common.

  • HP Tuners MPVI3 interface + credits: $500–$800
  • Custom Dyno Tune (professional shop): $400–$800
  • Remote Tune (email): $200–$500 (less expensive but requires wideband logging)

Do not skimp on tuning—an improper tune can destroy forged internals in seconds.

Labor Costs (If You Don't Build It Yourself)

If you lack the tools or experience to assemble an engine, professional labor adds significant cost. A reputable engine builder will charge for:

  • Short block assembly (clearancing, ring gaps, torque specs): $500–$1,200
  • Complete engine assembly (heads, intake, timing chain): $800–$1,500
  • Removal and installation (if swapping into vehicle): $1,500–$3,000

If you do your own assembly, set aside at least $300 for specialty tools (torque wrenches, micrometers, ring filer, piston ring compressor).

Total Estimated Cost Summary

Component Category Low-End High-End
Engine Block (including machining)$1,700$6,700
Eagle Forged Internals (pistons, rods, crank)$2,800$3,500
MDS Delete Parts (lifters, cam valley cover)$850$1,550
Performance Camshaft & Valve Springs$650$1,350
High-Performance Cylinder Heads$1,200$2,900
Fuel System Upgrades$700$1,450
Exhaust System$1,100$2,800
Cooling & Oil System$700$1,500
ECU Tuning$700$1,600
Subtotal (parts only)$10,400$22,350
Labor (if outsourced)$2,300$5,700
Total Estimated Cost$12,700$28,050

Note: Prices vary by region, brand, and availability. The low end assumes used or remanufactured parts and DIY labor; the high end uses all new premium components and professional assembly.

Tips for a Successful Build

  • Plan for extras: Gaskets, seals, ARP fasteners, timing chain dampers, and a new oil pump should be added to the budget—typically $500–$1,000.
  • Consider a turnkey crate engine: Companies like Blueprint Engines or Mopar Performance offer 550 hp HEMI crate engines with warranties, ranging from $12,000–$18,000. Sometimes that's cheaper than a custom build.
  • Don't forget the transmission: 550 hp will destroy a stock 4-speed or weak automatic. Budget for a built transmission (e.g., 727, 8HP70 or T56 Magnum) which adds $2,500–$5,000 more.
  • Break-in procedure: Forged pistons require a proper heat cycle and break-in on conventional oil before switching to synthetic. Follow the cam manufacturer's break-in routine exactly.

Frequently Asked Questions

Can I use Eagle forged parts with a stock HEMI block?

Yes, most Eagle forged components are designed to fit production HEMI blocks, but always verify at least the main journal size and piston pin height for your specific block (5.7L vs 6.4L).

Is 550 hp safe on the street with MDS delete?

Absolutely. Properly tuned, a forged 550 hp HEMI is perfectly streetable. You lose the MDS fuel economy benefit, but gain reliability and a more aggressive idle.

What if I want to add boost later?

Eagle forged internals can easily handle 600–800 hp with boost if you choose pistons with a lower compression ratio (9.5:1 or less). For 550 hp naturally aspirated, you can use 10.5–11.0:1 compression for better efficiency.

Final Thoughts

Building a 550 hp HEMI MDS delete setup with Eagle forged internals is a substantial investment—anywhere from $12,000 to $28,000 depending on your choices. But the reward is a durable, high-performance engine that can transform the driving experience of your HEMI-powered vehicle. Take the time to source quality parts, budget for machining and tuning, and don't rush the assembly. A well-built engine will provide years of reliable, grin-inducing power.

For further reading, check out Hot Rod's 550 hp HEMI build guide and Eagle Specialty Products' official site for component specs.