Speedtech Performance C10 Chassis Buyer’s Guide: ExtReme Street vs. ExtReme vs. ExtReme IRS

When it comes to upgrading your classic 1955–1998 GM Truck, Speedtech Performance offers three exceptional chassis options: the ExtReme Street, ExtReme, and ExtReme IRS. Each is engineered to deliver superior performance, catering to a range of driving styles from casual cruising to competitive racing. This guide will help you understand the unique features of each chassis, assisting you in selecting the perfect foundation for your truck build.

C10 Extreme Street Chassis for 67-72The base of the ExtReme Chassis – What is ExtReme?

Before we dive into the chassis options, let’s talk about what we are referring to when we say “ExtReme”. The Speedtech ExtReme front suspension delivers a lowered stance, wide tire fitment, maximized chassis rigidity, and serious handling performance — whether on the track or the street. Engineered with proprietary geometry and tuned with QA1 or JRi coilovers and a precision dual-power rack from Sweet Mfg., the system provides predictable, connected feedback with a refined ride quality that doesn’t compromise drivability.

Key Features

• Box-Welded Design: Delivers superior torsional rigidity for better handling under load and increased chassis longevity.
• Adjustable Coilover Shocks: Double-adjustable shocks allow fine-tuning of ride quality and handling response for street driving, autocross, or track use.
• Optimized Motion Ratio: Offers quicker shock response and more precise suspension tuning, ideal for autocross or track conditions.
• .005” Bump Steer: Near-zero bump steer throughout full suspension travel ensures stable, predictable steering input.
• Optimized Ackerman Geometry: Provides up to 20% more inside tire grip for sharper turn-in and faster exits.
• 7075 Forged Aluminum Spindles: Aircraft-grade forged components with optimized geometry improve KPI/SAI and reduce scrub radius for more mechanical grip.
• 30° ± Steering Angle: Maintains excellent maneuverability and responsiveness even with wide tires and aggressive alignments.
• C5/C6 Brake Pattern & C7 Hubs: Factory-fit, sealed hub system offers low maintenance and opens a wide range of aftermarket brake options.
• Custom Ride Height & Tire Fitment: Tailor your stance without compromising performance—accommodates 315/30/18s with full travel and clearance.

Choosing the Right Chassis for Your Build

• ExtReme Street: Ideal for those prioritizing comfort and ease of installation, perfect for daily drivers and show trucks.
• ExtReme: A balanced choice for enthusiasts who desire both street comfort and the ability to perform on the track.
• ExtReme IRS: Best suited for high-performance builds where superior handling and customization are essential.

Each of these chassis options from Speedtech Performance is crafted with precision and quality, ensuring that your C10 build meets your specific driving goals. Whether you’re cruising the streets or dominating the track, there’s a Speedtech chassis designed to elevate your driving experience.

C10 Extreme Chassis for 67-72 – Built By JRW Customs