Crate Engine Builder Kit by Butler, 450-550hp, 4.250 Str, 460-474 cu. in. Ready to Assemble

Our Butler Crate Engine Builder Kits have the following parts and more

• 400, 428, or 455 Pontiac Block with Option for 4-Bolt Main With Main Studs upgrade, Dip Stick tube installed
• Butler Rotating Assembly- With Crank, H-Beam Rods, Forged Pistons and bearings
• Cast or Forged Crank 4.250 Stroke
• H-Beam Rods 6.800"
• BP Forged Pistons and Pins
• Total Seal Rings
• C77 Race Bearings
• BP Billet Gears and Chains
• High Volume Oil Pump
• BP/COMP Hyd Roller Cam
• Hyd Roller Lifters
• BP Custom Pushrods 5/16 .116" Wall
• Harmonic Damper
• Roller Rockers
• Butler Built Heads with choice of CNC Porting
• Carb or EFI of your choice
• Stock Type or Canton Oil Pan & Pickup
• Port Matched Intake
• TPP Valley Pan
• Flowkooler Water Pump
• New 11 Bolt Timing Cover, Plates, and Sleeves
• Ignition Kit
• IMI Starter
• Engine Paint and Valve Cover Options
• All gaskets and stainless steel accessory and ARP fasteners

The Block

We start with the exact same blocks you would build on your own. It's what we do to take these old dirty blocks that you see here to a beautiful custom built Butler engine. It takes many critical steps in order to become the proper foundation to be a custom Butler Performance engine.

Step 1- 3 Step Cleaning Process

-Baked, Blasted, and Cleaned

Step 2- Visually Inspected

Step 3- Magnafluxed/Sonic Tested

Step 4- Replace Dowel Pins

Step 5- Align Bored (if required)/ Align Honed

Step 6- Bored and Honed with a Torque Plate

***Due to the fact that these 40 plus year old blocks cleanup of cylinders varies on a block to block basis. Therefore your final bore size will be determined at this step. Sufficient wall thickness will be verified once again regardless of final bore size. We will select the smallest bore available for your particular block unless you request a larger bore size/larger cu.in.***

Step 7- Square Decked

Step 8- Deburred/ Final Multi Prep Process

 (It takes over a full days work for the final prepping process. Including tapping all bolt holes and cleaning all oil galleys)

Step 9- Final Jet Wash/Cleaning/Wipe Down

Step 10- Ready for Assembly

All rotating assemblies sold by Butler Performance, regardless of brand, are neutrally balanced in our shop by our experienced machinists.

Images show assembled with optional parts. Contact us for detailed quote for your application and specifications.

Drive, accessory pulleys, and March Serpentine systems sold separately

Air cleaner or drop base sold separately

Don't sweat the details. Once order is places one of the Butler Engine Tech's will contact you to finalize any details related to your specific car, application, and final details. Some of these details will be valve cover logo, breather location, and any other parts needed for your specific application. We will answer any questions you may have and get your build processed and in line for machining.