Atlas 4200 to LS Transmission Adapter Kit
The Atlas 4200 to LS transmission adapter kit is the most complete solution for running a GM Atlas 4200 inline-six engine with LS-based transmissions. Designed for strength, precision, and ease of installation, this kit allows you to pair the Atlas 4.2L engine with a wide range of LS manual and automatic transmissions.
Machined from 6061 billet aluminum, this adapter system ensures precise alignment and long-term durability—making it ideal for high-performance builds, off-road applications, and custom swaps.
Whether you're building a turbo Atlas setup or a unique inline-six project, this kit provides a reliable, OEM-based solution without the need for custom fabrication.
What’s Included
- Billet Bellhousing Adapter Plate
- Inner Crank Adapter (retains factory Atlas starter ring gear)
- Outer Crank Adapter (LS bolt pattern + proper engagement)
- Starter Spacer
- Complete Hardware Kit
Optional:
- Lower Adapter Kit for full bellhousing coverage and sealed fit
Key Features
Atlas 4200 to LS Transmission Compatibility
Run the Atlas 4.2L inline-six with LS-pattern transmissions, including:
- 4L60E / 4L80E
- TH350 / TH400
- Powerglide
- T56 / TR6060
- AR5
- CD009 and more
Precision CNC-Machined Billet Construction
Made from 6061 billet aluminum for accurate fitment and long-term strength.
True Bolt-On Installation
No cutting, welding, or fabrication required—designed for a straightforward Atlas swap.
Supports High Horsepower Builds
Compatible with 11” and 12” clutch setups, supporting over 1000+ WHP with single, twin, or triple disc options.
Retains Factory Starter Functionality
Inner crank adapter allows use of the OEM Atlas starter and ring gear, simplifying installation and parts sourcing.
OEM-Based LS Components
Built around widely available LS components for easy serviceability and upgrades.
What You’ll Need for Your Atlas 4200 LS Swap
Atlas 4200 Engine (GM 4.2L Inline-Six)
Found in vehicles like:
- Chevy Trailblazer
- GMC Envoy
- Chevy SSR
- Buick Rainier
LS-Based Transmission
Compatible with both manual and automatic LS-pattern transmissions, depending on your build goals.
Clutch or Torque Converter Setup
Supports 11” and 12” LS-style clutch systems or appropriate automatic transmission setups.
GM LS Bellhousing (if applicable)
Required depending on transmission choice and setup.
Starter
Uses the factory Atlas 4200 starter with included spacing components.
Perfect For
- Atlas 4200 (LL8) engine swaps
- Turbo Atlas inline-six builds
- Off-road and rock crawler setups
- Drift and street builds
- Builders wanting a unique inline-six LS transmission setup
Why Choose FABbot
We specialize in building solutions for swaps that others overlook. This kit makes it possible to run a modern LS transmission behind the Atlas 4200 inline-six with proper alignment, strength, and reliability.
- Complete adapter system (not just a plate)
- Uses OEM components for easier maintenance
- Supports high horsepower applications
- Designed for real-world builds
📞 Questions or Want to Check Stock?
Call our sales line at 763-670-6941 — we’re happy to help!
