*Shown With Optional Upgrades

LS3 416CI 575HP Crate Engine

Estimated Cost From: $13,095.00

Our LS3 416CI 575HP stroker crate engine package can be dyno tested ready for installation. This build features the an aluminum LS3 6 bolt block. Comes ready to install with the Muscle Car oil pan. We can also assist you in picking out the correct motor mount and header combo that will fit your hot rod. If you are in need of a serpentine pulley kit complete with components or a transmission we can assist you with that as well. All our LS series crate engines can be custom painted “customers choice of color”.

  • LS3 416CI 575HP Long Block:
  • Fully Machined LS3 aluminum Block
  • Forged steel 4.00” stroke crankshaft (Eagle, Scat, or LPC)
  • 6.125″ Connecting Rods With ARP Bolts (Eagle, Scat, or LPC)
  • Performance Forged Pistons (Mahle, Icon, DSS, or JE)
  • Complete Assembly Balanced (Internal)
  • Performance rings hand filed to match application
  • Custom Ground Hydraulic Roller Camshaft
  • Hydraulic Roller Lifters
  • Performance Timing chain set
  • Melling Oil pump
  • LS3/L92 Rectangle Port Aluminum Performance Cylinder Heads
  • 2.165 Pro Series Intake Valves
  • 1.590 Pro Series Exhaust Valves
  • 1.295” Dual Performance Valve Springs
  • 7 Degree Valve Retainers And Locks
  • Roller Rocker Arms
  • Chrome Moly Pushrods
  • Main bolts
  • ARP Head bolts
  • Aluminum Timing And Rear Cover
  • Aluminum Valley Tray
  • Muscle Car Stroker Oil Pan
  • Aluminum Valve Covers (Black, or Polished)
  • Harmonic Balancer
  • Water Pump
  • Fabricated Aluminum Intake Manifold (Black, or Shinny)
  • Cable Driven Throttle Body (Black, or Shinny)
  • Fuel Injectors
  • Fuel Rails
  • Engines are photo documented during the building process
  • 1 Year Unlimited Mileage Warranty

Customize Your Crate Engine

  • Long Block Spec’s Above Plus The Following
  • LS3 Style Coils
  • Coil Harness
  • Spark Plugs
  • 8.5mm Ignition Wires
  • Holley Terminator X ECU
  • Engine Wiring 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
  • 2 Year Unlimited Miles Warranty

Break In And Tune Yourself

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

Hot Run Tested

  • Proformance Unlimited will do the initial break in.
  • Create base tune.
  • Break in rings
  • Check for leaks
  • Heat cycle the engine
  • Check for proper oil pressure


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

Alternator Only

Add $1,675

Alternator, Power Steering 

Add $1,875

Alt, PS, AC 

Add $2,300

4L80E Transmission Package

Starting @ $4,950

TKO-600 Transmission Package

Starting @ $5,400

Becool Radiator Combo

Starting @ $1,399

Fuel Tank With Electric Pump

Starting @ $550

Conversion Install Package:

Starting @ $1,550

All of the Proformance Unlimited turn-key LS engine packages will include an engine harness and an ECM to allow for full engine control and the best driving characteristics possible. Most other suppliers of turn-key engine packages will use out-of-date MEFI ECM’s and harnesses that do NOT allow the engine to make fueling or timing changes when running, nor will they allow for any needed changes with varying altitude. All of our turn-key engine packages will allow your engine to run and function exactly like a new car straight off of the production line! This will not only help the power output, but it will also help to maximize the fuel mileage! If you choose the Fitech ultimate efi w/trans control this will allow for full control of a GM’s 4-speed overdrive 4L60E, 4L65E, 4L70E, and 4L80E electronically-controlled transmission. The competition’s MEFI ECM and harness does not have this capability.

All of our turn-key engine packages will come standard with the GM Performance aluminum valve covers with a coil pack relocation kit and GM Hot Rod Oil Pan Kit. However, we do offer upgrades for all of these items, which are listed above in the drop-down menus. Let us know if you are looking for an item that is not listed, and we will be glad to provide you with a price! The aluminum coil pack relocation kit allows you to hide the ignition coil packs anywhere you would like under the hood, which provides you with a clean and uncluttered engine bay.

All Proformance Unlimited turn-key engine packages will come standard with a one-year, unlimited-mile warranty as standard! This will require all tuning to be performed by us. We stand behind our work, and when you purchase a Proformance Unlimited engine you are not only buying the parts but also the knowledge, experience, and know-how! We know what works and what is required to complete the installation!