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Butler Performance Custom Short Block Kit, 400 Block, 4.500" str (Unassembled)


  • Customized Butler Performance Short Block Kit
  • Option to send us your block
  • Choose Bore Size, Stroke, Crank, & Rod
  • 4.500" Stroke
  • Create a custom package tailored to you
  • All short blocks undergo the "Butler Process"

Availability: Contact us for lead time. Ships to business address. Residential or liftgate are available for additional charges
Pricing: $4,499.00

Customize Your Item

- Choose Your Assembly -
 * required
- Choose Main Cap Upgrade -
 * required


434-494 CI short block kit
Complete Internally Balanced longrod rotating assembly & 
high-performance prepped block

  • 4.500" stroke forged crank    (4-Bolt Billet Mains Caps recommended for 4.5" stroke)
  • Internally Balanced
  • Ross Racing Pistons (Bore 4.155 - 4.181 440 grams)-Flat Top (Dish or Dome/additional charge)
  • H-Beam Rods
  • File fit rings
  • Performance Rod bearings
  • Performance Main bearings
  • 400 Performance Prepped Block
    • cleaned
    • magnafluxed
    • sonic tested
    • completely deburred
    • bored and honed with torque plate
    • line honed with ARP main studs
    • deck squared
    • cam bearings and brass freeze plugs installed
    •  ready to assemble
  • Can be upgraded with various options

Included reusable engine cradle

Images for display purposes only and could show optional parts. Contact us for a custom quote for your application and specifications

Compression Calculator

400 Block Head cc w/-8cc Flat top
Stroke Bore 72cc 87cc 96cc
3.750" 4.155" 10.38 9.02 8.38
  4.181" 10.48 9.11 8.46


11 9.55 8.87
  4.181" 11.12 9.65 8.96
4.210" 4.155" 11.53 10 9.28
  4.181" 11.65 10.1 9.38
4.250" 4.155" 11.63 10.09 9.36
  4.181" 11.75 10.19 9.46
4.500" 4.155" 12.25 10.62 9.85
  4.181" 12.38 10.73 9.96
Click here to use our compression calculator to calculate compression with thicker head gaskets, decked block, or other variables.


  • BP-SB-Kit-400-4500
  • BP-SB-Kit-400-4500
  • Butler Performance
  • Contact us for lead time. Ships to business address. Residential or liftgate are available for additional charges
  • New

Customer Reviews

Comment Total Reviews (1)

461 Stroker build
  • Currently 5/5 Stars

Reviewed by: Luke01/11/2018 08:48PM

Product ownership: Less than 1 month

Purchased from: Butler Performance Inc.

Took about 6 weeks for machining to be done and arrive at my address. Shipped on a pallet inside a wooden cage and wrapped in plastic. Inspection was flawless.
Block came bare. ALL plugs on engine were removed for cleaning. Freeze plugs on sides of block were put back in by Butler but all galley plugs came uninstalled so that I could inspect the oil galleries myself. Coolant drain plugs came as Petcock valves.
Rods needed to be assembled to the pistons. Cam bearings were installed by Butler along with dipstick tube. All clearances were well within spec. I opted to have them paint the block. Looks great and even sent the leftover paint with engine kit.
Kit met all of my expectations and am very happy that I decided to have the Pontiac experts at Butler to do the machine work on my 400.

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