Katech Gen IV LS3 416ci Naturally Aspirated Short Block

Katech Gen IV LS3 416ci Naturally Aspirated Short Block

Forged 416ci Stroker Assembly, Hand-Assembled by Katech Master Engine Builders.

The Katech Gen IV LS3 416ci Naturally Aspirated Short Block combines a brand-new production GM LS3 block with a Callies forged crankshaft, Callies forged connecting rods, and CP-Carrillo forged pistons. Hand-assembled by Katech Master Engine Builders in Clinton Township, Michigan, USA, it provides the foundation for a compatible naturally aspirated LS performance engine.

A 4.070-inch bore and 4.000-inch crankshaft stroke provide approximately 416 cubic inches of displacement. The block is CNC clearanced to accommodate the stroker rotating assembly.

The specified compression ratio is 10.9:1 with a stock LS3 combustion chamber. Final compression ratio depends on chamber volume, head gasket dimensions, and piston deck clearance in the completed engine.

Features & Benefits

• Brand-New Production GM LS3 Engine Block
• Approximately 416 Cubic Inches of Displacement
• Block CNC Clearanced for the Stroker Rotating Assembly
• Callies Forged Crankshaft with a 4.000-Inch Stroke
• 58x or 24x Crankshaft Reluctor Configuration Available
• Callies Forged Connecting Rods
• CP-Carrillo Forged Pistons with Rings and Pins
• 4.070-Inch Cylinder Bore
• Specified 10.9:1 Compression Ratio with a Stock LS3 Combustion Chamber
• Clevite Bearings
• Block Oil and Coolant Plugs Included
• Hand-Assembled by Katech Master Engine Builders in Clinton Township, Michigan, USA

Technical Specifications

• Engine Platform: GM Gen IV LS3
• Displacement: Approximately 416ci
• Block: New Production GM LS3 Block
• Block Preparation: CNC Stroker Clearancing
• Bore: 4.070 Inches
• Stroke: 4.000 Inches
• Crankshaft: Callies Forged
• Crankshaft Reluctor: 58x or 24x, Depending on Selected Configuration
• Connecting Rods: Callies Forged
• Pistons: CP-Carrillo Forged
• Rings and Pins: Included
• Bearings: Clevite
• Specified Compression Ratio: 10.9:1 with a Stock LS3 Combustion Chamber
• Intended Application: Naturally Aspirated Engine Builds

What's Included

• New GM LS3 Block with CNC Stroker Clearancing
• Callies Forged Crankshaft in the Selected 58x or 24x Configuration
• Callies Forged Connecting Rods
• CP-Carrillo Forged Pistons, Rings, and Pins
• Clevite Bearings
• Block Oil and Coolant Plugs
• Katech Short Block Assembly

Sold Separately: Valley cover and rear cover.

This listing is for an assembled short block. Additional components are required to complete a running engine.

Application & Fitment

The Katech Gen IV LS3 416ci Naturally Aspirated Short Block is intended for compatible LS-based engine builds using naturally aspirated induction. Installation depends on the selected cylinder heads, camshaft, intake manifold, oiling system, electronics, and vehicle components.

• Compatible LS3-Based Naturally Aspirated Performance Builds
• Custom LS Engine Installations with Compatible Supporting Systems
• Applications Using the Appropriate 58x or 24x Engine Management Configuration

Select the crankshaft reluctor configuration to match the intended control system. A 24x or 58x selection alone does not establish complete electronics compatibility; camshaft position sensing and other supporting components must also be matched.

Configuration & Installation

Choose the 58x or 24x crankshaft reluctor configuration appropriate for your build before ordering. Plan the cylinder heads, camshaft, induction system, and fuel requirements around the completed engine combination.

Install the short block as part of your own engine project or discuss installation services with Katech.

Important Build Notes

• Verify Final Compression Ratio with the Selected Cylinder Heads, Head Gaskets, and Piston Deck Clearance
• Check Piston-to-Valve Clearance with the Selected Camshaft and Cylinder Heads
• Confirm Crankshaft and Camshaft Position Signal Compatibility with the Engine Management System
• Match Fuel Selection, Fuel System Capacity, and Calibration to the Completed Engine
• Select an Appropriate Oil Pump, Oil Pan, and Cooling System
• Follow the Applicable Assembly, Startup, and Break-In Procedures

Why Choose Katech

A naturally aspirated stroker engine relies on a coordinated combination of displacement, compression, airflow, and camshaft selection. The Katech Gen IV LS3 416ci Naturally Aspirated Short Block establishes that foundation with a new GM block, forged rotating components, and assembly by Katech Master Engine Builders.

The available reluctor configurations allow the short block to be specified around the intended electronics, while Katech's engine development experience helps guide the supporting combination.

For configuration and installation questions, contact Katech Technical Sales at 586-791-4120.