SKU: 400840 | UPC: 808422008402
Borla 400840 CrateMuffler Chevrolet Small Block 350/383/406 CID V8 High Output 3" Offset/Offset S-Type Oval Muffler
The Borla 400840 CrateMuffler is purpose-built for Small Block Chevrolet high output 350/383/406 CID V8 crate and custom engines. It delivers aggressive Borla sound, gains in horsepower and torque, better fuel economy, and drone elimination through directional tuning. Install this 14" x 4.35" x 9.1" oval muffler for precise fit and motorsport performance in hot rods, muscle cars, and engine swaps.
Key Features
- T-304 Stainless Steel: Corrosion-resistant material ensures durability in all conditions.
- Directional Design: Tuned for SBC engine family with outlet marked by welded bracket to cut drone.
- Precise Sizing: 14" body length, 19" overall, 3" offset inlet/outlet for seamless 3" piping integration.
- CNC Manufacturing: Computer-controlled production for exact fit and flow efficiency.
- Engine-Specific Tuning: Optimizes sound and power for 350/383/406 CID high output V8s.
Product Notes
- Muffler is directional; align outlet end with bracket toward rear of vehicle.
- Intended for crate and custom high output Small Block Chevy V8 builds.
- Ships ready for 3" exhaust systems with pipe-style connections.
Installation Notes
- Professional installation recommended.
- Verify inlet/outlet orientation before welding or clamping.
- Compatible with standard 3" exhaust hangers and hardware.
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| Crate Engines | Chevrolet | Small Block V8 | 350/383/406 CID High Output |
| Custom Builds | Chevrolet | SBC Engine Swap | Hot Rod/Muscle Car |
Why Choose Borla?
- Pioneer in stainless steel exhaust for classics and race cars.
- Delivers power gains, torque, and signature exhaust note.
- Million-Mile Warranty covers every CrateMuffler.
Frequently Asked Questions
-
Q: Which engines fit this CrateMuffler?
A: Designed for Chevrolet Small Block 350/383/406 CID V8 high output crate and custom motors. -
Q: What material construction?
A: T-304 stainless steel, all-welded for strength and rust resistance. -
Q: What warranty coverage?
A: Backed by Borla Million-Mile Warranty for performance and longevity.
Shipping & Handling
- Method: UPS Ground or FedEx Ground
- Availability: In stock - ships same or next business day
- Packaging: Original Borla box, 21" x 10" x 10"
- Weight: 11 lbs

Borla
Discover the Borla Exhaust Systems collection at Black Ops Auto Works, featuring premium American-made exhaust solutions engineered for superior performance, sound, and durability. With decades of innovation and multiple U.S. patents, Borla exhaust systems are trusted by enthusiasts seeking aggressive tone, optimized airflow, and vehicle-specific fitment. Borla Cat-Back & Axle-Back Exhaust Systems Upgrade your vehicle’s sound and performance with Borla cat-back exhaust systems engineered to deliver increased horsepower, improved exhaust flow, and signature Borla tone. For targeted sound enhancement and rear-section upgrades, explore Borla axle-back exhausts, designed for easy installation and refined acoustics. Borla Mufflers, Resonators & Exhaust Components Fine-tune exhaust tone and volume using Borla performance mufflers and Borla exhaust resonators, precision-tuned for optimal sound control and airflow efficiency. Supporting components like Borla mid-pipes, X-pipes, and ... View Our Borla Products...
Exhaust Systems
Find the right performance exhaust system for your car, truck, or SUV with our curated selection of stainless-steel upgrades engineered for power, sound, and reliability. Browse proven layouts like cat-back, axle-back, and turbo-back systems, dial in flow with headers & manifolds and downpipes, or tailor your tone with mufflers & resonators and polished exhaust tips. We also stock emissions-minded solutions including direct-fit catalytic converters and universal catalytic converters. Shop top brands such as Akrapovič, AWE Tuning, Borla, Invidia, GReddy, Perrin, Banks Power, and Gibson. Every option is selected for quality construction (think mandrel-bent tubing and precise welds) and bolt-on fitment, and our Year/Make/Model search makes it easy to match parts to your build—upgrade throttle response, unlock a deeper, refined exhaust note, and enhance your vehicle’s style with components that deliver performance you can feel. View Our Exhaust Systems Products...
Mufflers
Welcome to our Mufflers collection, where performance meets style. Our curated selection offers a variety of mufflers to enhance your vehicle’s sound and efficiency. Whether you’re looking for a subtle upgrade or a loud statement piece, we have the perfect options for you. Why Choose Our Mufflers? High-Quality Materials: Crafted from durable materials to ensure longevity and reliability. Performance Enhancement: Designed to improve your vehicle’s exhaust flow and overall performance. Stylish Designs: Available in various styles to suit your personal taste and vehicle aesthetics. Easy Installation: Many of our mufflers come with easy-to-follow installation instructions for a hassle-free upgrade. Featured Products Check out some of our top-selling mufflers: Performance Muffler X1: Boosts horsepower while providing a deep, aggressive sound. Eco-Friendly Muffler Series: Designed to reduce emissions without compromising on performance. Customizable Muffler Kit: Personalize you... View Our Mufflers Products...



