*Shown With Optional Upgrades

426CI Hemi 640HP Crate Engine

Estimated Cost From: $17,995.00

Proformance Unlimited offers a full line of Gen III Hemi based turn-key drop in ready crate engines designed for hot rods and muscle cars. Our 426CI 640HP Gen III Hemi Build is where new school performance meets old school looks. We have developed a complete line of fuel injected Late Model Hemi based power plants to fit almost everyone’s needs. If you don’t see something you want give us a call and we will design it for you. Our vision on these engines is to bring back the really cool looks from yesteryears engines with today’s reliability.

  • Dodge Gen III Hemi 426CI 640HP Crate Engine:
  • A Gen 3 BGE Hellcat – Apache Block
  • Bored And Honed With Deck Plate
  • Mains Have Been Aligned
  • Block Has Been Square Decked
  • Dura Bond Cam Bearings Installed
  • Block Painted With 3 Coats Of High Temp Ceramic Engine Paint Choice Of Color
  • 4340 Forged Steel 4.050 Stroker Crankshaft (Eagle)
  • 4340 Bushed Connecting Rods (Eagle)
  • High Performance Forged Pistons (Mahle, Diamond, or DSS)
  • Performance Rod And Main Bearing (Clevite, or King)
  • Performance Rings Hand Filed To Match Application
  • The Complete Rotating Assembly Will Be Balanced
  • Custom Ground High Performance Street Camshaft
  • Three-piece True Double Roller Timing Set
  • Hydraulic Roller Lifters
  • Roller Lifter Retainer Tray
  • Performance Aluminum Cylinder Heads (Edelbrock, or AFR)
  • Performance Valve Springs And Retainers (to match camshaft)
  • Chrome Moly Push Rods
  • Shaft Mount Rocker Arms
  • Melling Oil Pump
  • Melling Oil Pick Up
  • Pro Touring Oil Pan (To Match Application)
  • Dipstick And Tube
  • Aluminum Timing Cover
  • Engine will Be Assembled With All New Bolts
  • ARP Head Bolts
  • Fel-Pro/Mahle Performance Gaskets
  • Harmonic Balancer
  • Intake Manifold
  • Throttle Body
  • Gen III Hemi Style Coil Packs
  • Calibrated ECU (Holley Terminator X)
  • Main ECM Engine Wiring Harness
  • Coil Pack Harness
  • Fuel Injector Harness
  • Wide Ban O2 Sensor
  • Intake Air Temperature Sensor
  • Crankshaft Position Sensor
  • Camshaft Position Sensor
  • Engine Coolant Temperature Sensor
  • Manifold Air Pressure Sensor
  • Oil And Filter
  • Spark Plugs
  • Fuel Injectors
  • Engines Will Be Photo Documented During The Building Process
  • 2 Year Unlimited Millage Warranty

Customize Your Crate Engine

Break In And Tune Yourself

  • Customer Is responsible for
  • Tuning EFI
  • Ring Break-In

Dyno Tested And Tuned (Doug’s Way)

Proformance Unlimited measures over 30 parameters that are monitored and logged to the computer during each engine test. A complete printout, including graphs.

We tune your engine on the dyno for maximum power. No more endless trial and error methods at the track are required. You see your results instantly! Dynamometer testing costs a fraction of what you have invested. Take the guesswork out of tuning – by dynoing !


  • Your engine will be broken in under various load conditions
  • Tested in real world conditions through headers and mufflers
  • Precise horsepower and torque rating with graph and numerical print out
  • Induction system tuned for optimal performance
  • Dyno session video taped

With all the after market parts made readily available today, we can custom design your crate engine to deliver extremely powerful street performance or off road track use. All our engines are built with precision to perform with quality and assurance you can depend on.

Proformance Unlimited we are here to help design and build the combination that best suits your knowledge level and over all experience, so your vehicle will out perform your expectations. Please browse our engine combinations listed below. Proformance Unlimited is best known for our precision custom designs. If you have any questions and would like Proformance Unlimited to build your next engine feel free to call Doug or Steve.