Katech Gen IV LS7 Street Attack Short Block

Katech Gen IV LS7 Street Attack Short Block

New GM LS7 Block with Forged Components, Hand-Assembled by Katech Master Engine Builders.

The Katech Gen IV LS7 Street Attack Short Block combines a brand-new production GM LS7 block with a Callies forged crankshaft, Callies forged connecting rods, and CP forged pistons. Hand-assembled by Katech Master Engine Builders in Clinton Township, Michigan, USA, it provides the foundation for a compatible naturally aspirated LS7 performance engine.

The rotating assembly features a 4.000-inch-stroke crankshaft with a 58x reluctor and 4.125-inch pistons. Clevite main and rod bearings and block oil and coolant plugs are included.

The specified compression ratio is 11.2:1 with a stock LS7 combustion chamber. Higher compression ratios are available upon request. Final compression ratio depends on the selected chamber volume, head gasket dimensions, and piston deck clearance.

For completed engine builds targeting 750+ HP, confirm the required cylinder heads, camshaft, induction, exhaust, fuel, and operating range with Katech. Output depends on the complete engine combination and calibration.

Features & Benefits

• Brand-New Production GM LS7 Engine Block
• Designed for Naturally Aspirated LS7 Performance Builds
• Callies Forged Crankshaft with a 4.000-Inch Stroke
• 58x Crankshaft Reluctor
• Callies Forged Connecting Rods
• CP Forged 4.125-Inch Pistons with Rings and Pins
• Specified 11.2:1 Compression Ratio with a Stock LS7 Combustion Chamber
• Clevite Main and Rod Bearings
• Block Oil and Coolant Plugs Included
• Higher Compression Ratios Available upon Request
• Hand-Assembled by Katech Master Engine Builders in Clinton Township, Michigan, USA

Technical Specifications

• Engine Platform: GM Gen IV LS7
• Block: New Production GM LS7 Block
• Piston Diameter: 4.125 Inches
• Crankshaft Stroke: 4.000 Inches
• Crankshaft: Callies Forged
• Crankshaft Reluctor: 58x
• Connecting Rods: Callies Forged
• Pistons: CP Forged
• Rings and Pins: Included
• Main and Rod Bearings: Clevite
• Specified Compression Ratio: 11.2:1 with a Stock LS7 Combustion Chamber
• Compression Options: Higher Ratios Available upon Request
• Intended Application: Naturally Aspirated Engine Builds

What's Included

• New Production GM LS7 Block
• Callies Forged Crankshaft with 58x Reluctor
• Callies Forged Connecting Rods
• CP Forged Pistons, Rings, and Pins
• Clevite Main and Rod 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 LS7 Street Attack Short Block is intended for compatible naturally aspirated LS7-based engine builds. Vehicle installation depends on the completed engine configuration, oiling system, electronics, and installation components.

• Compatible LS7-Based Naturally Aspirated Performance Builds
• Custom LS Installations with Compatible Supporting Systems
• Engine Combinations Using Compatible 58x Engine Management

Verify cylinder head, camshaft, oiling system, and engine management compatibility before completing the build.

Compression Ratio Options

Higher compression ratios are available upon request. Select the compression ratio around the intended fuel, camshaft, cylinder heads, and operating conditions. Changes to chamber volume, head gasket thickness, or piston deck clearance affect the final ratio.

Important Build Notes

• Verify Final Compression Ratio for the Completed Engine Combination
• Check Piston-to-Valve Clearance with the Selected Camshaft and Cylinder Heads
• Match Fuel Selection and Calibration to the Compression Ratio and Intended Use
• Confirm Crankshaft and Camshaft Position Signal Compatibility with the Engine Management System
• Select an Appropriate Oil Pump, Oil Pan, and Supporting Oiling Components
• Match the Cooling System and Fuel System to the Completed Engine's Requirements
• Follow the Applicable Assembly, Startup, and Break-In Procedures

Why Choose Katech

The LS7 platform offers a foundation for naturally aspirated performance, but the finished result depends on how the engine's components work together. The Katech Gen IV LS7 Street Attack Short Block combines a new GM block and forged rotating components with hand assembly by Katech Master Engine Builders.

Available compression options allow the build to be planned around its fuel and performance goals, while Katech's LS7 development experience helps guide the supporting combination.

For compression options and complete engine configuration questions, contact Katech Technical Sales at 586-791-4120.