408ci LY6 Boosted Competition Short Block


The LY6 408ci Boosted Competition short block uses a new GM LY6 cast iron block with 4.030″ bore to produce the large 408ci.

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Grand total


  • GM LY6 Cast Iron Block Performance Honed with Torque Plate
  • Bore Size 4.030″
  • Resurfaced to Match Pistons
  • Line Honed with ARP Main Studs
  • Blueprinted Oil Clearances
  • All New GM Block Plugs Installed
  • New Durabond Cam Bearings Installed


  • Wiseco Custom Forged Boost Pistons


  • King H-Series Main and Rod Bearings


  • Callies Comp Star 4340 Forged Steel
  • Stroke 4.000”
  • Your Choice of 24x or 58x Reluctor Wheel (Billet 24X Reluctor Wheel is an Extra $150″)
  • Internally Balanced Front and Rear


  • Callies Comp Star 4340 Forged Steel H-Beam
  • 6.125” Length
  • ARP 2000 Rod Bolts


Technical Links: (Coming Soon)


  • Installing Windage Tray, Oil Pump Pick Up and Covers
  • Installing LS Harmonic Balancer
  • Torque Specs for Entire Engine
  • How to Set Pushrod Preload on LS Engine
  • How to Properly Prime the LS Oil Pump
  • Recommendations; Oil, filter, spark plugs

Calling all turbo and supercharger fans! The Golen Engine 408ci LY6 Boosted Competition Short Block is here, and it’s a force to be reckoned with. We start with a tough GM LY6 cast iron block, beefed up with ARP main studs and Durabond cam bearings. At its heart lies a Callies Comp Star 4340 forged steel crankshaft with 8 counterweights, plus Callies Comp Star H-Beam rods with ARP 2000 rod bolts.

We’re using Wiseco 2618 forged pistons with GFX ring sets – perfect for handling big boost. This engine is fully assembled, balanced, blueprinted, and kitted out with King bearings. It’s built to take up to 20 psi of boost from either superchargers or turbos, making it a beast in the boost world.

Need more parts to finish your build? We’ve got you covered with Cometic MLS head gaskets, ARP Head studs, and our own Golen Engine Aftermarket LS3 CNC Ported heads. These heads are the real deal, with .750″ thick decks to keep all that boost where it belongs.

And don’t sweat the assembly – we offer full tech support, along with a bunch of tech links and videos for off-hour help. The Golen Engine 408ci LY6 Boosted Competition Short Block is your ticket to dominating the boosted scene. Let’s get building!

Additional information

Weight 350 lbs
Dimensions 38 × 26 × 27 in