Anyone planning an LS swap or a lifted/ lowered GM truck needs a reliable transmission crossmember. This guide highlights five crossmembers that balance strength, adjustability, and compatibility across 1963–1987 C10/C20/BLAZER/Suburban body styles and related GM platforms. The top picks are best for different buyer needs: ease of install, extreme adjustability, or maintaining factory driveline geometry. The following concise table compares each option to help buyers decide quickly.
| Product | Best For | Key Benefit |
|---|---|---|
| GSI Machine & Fabrication Crossmember | LS swaps and high-powered builds | Adjustable pinion height, high-strength DOM tubing |
| ELITEWILL Adjustable Crossmember | All GM automatics with no drilling | Center tab adjustability for multiple transmissions |
| ALMULOO Adjustable Crossmember | Budget-conscious, durable lift/ lower setups | Stable steel construction, improved stability |
| JY PERFORMANCE Crossmember | Classic 1964–1987 pickups and SUVs | Maintains factory transmission angle with adjustability |
| Trans-Dapt S10 Crossmember | S10/S15 LS swap seekers | Direct attachment for LS engine swaps |
Note: Each option serves different installation goals—whether you need precise drive shaft alignment, easy compatibility with multiple GM transmissions, or a rugged platform for a heavy-duty build. Review fitment notes and the list of supported transmissions to ensure compatibility with your vehicle and planned drivetrain configuration.
GSI Machine & Fabrication Crossmember
The GSI crossmember is designed for 1963–1987 Chevy and GMC trucks, including C10, C20, C30, Suburbans, and Blazers. It features adjustable pinion height to fine-tune driveline angles, and the unit can be flipped to lower the transmission height for slammed or performance builds. This crossmember uses heavy-duty American steel and is finished with a robust powder-coated black surface for corrosion resistance. Best for drivers building or restoring classic GM trucks who want precise pinion angle control and the option to lower the transmission height without fabricating new brackets.
Who it’s best for: Builders pursuing LS or traditional automatic transmissions who require versatile height adjustment and strong rigidity. Why: The design supports high-horsepower applications and offers flexible positioning, reducing vibrations and drivetrain stress when paired with compatible mounts.
Caution: The crossmember requires proper alignment during installation; incorrect height adjustment can cause drive shaft or exhaust interference if not checked in the frame context.
ELITEWILL Adjustable Crossmember
ELITEWILL offers a center-tab adjustable crossmember compatible with 1963–1987 GM trucks (C10, C20) and Blazers/Suburbans. It supports multiple automatic transmissions (Power Glide, TH-350, TH-400, 700R4) without needing new frame holes. The heavy-duty steel with a black powder coating provides corrosion resistance and long-term durability. Best for builders seeking a “plug-and-play” crossmember that accommodates a range of automatics while preserving frame integrity.
Who it’s best for: Enthusiasts who swap in older or modern GM automatics and want straightforward installation. Why: The adjustable center tab enables the correct transmission height across configurations, reducing the risk of misalignment.
Caution: Some installations may require additional hardware or minor frame clearance checks depending on exhaust routing and suspension setup.
JY PERFORMANCE Adjustable Crossmember
The JY PERFORMANCE crossmember is designed for 2WD 1964–1987 Chevy C10, C20 trucks, Blazers, and Suburbans. It features heavy-duty steel construction with a black powder-coated finish and an adjustable crossmember design that maintains the factory transmission angle for proper driveshaft alignment. Best for traditional builds that retain factory geometry while adding a modernized crossmember for lift or drop adjustments.
Who it’s best for: Classic GM truck owners seeking a balance of ease of use and maintained driveline geometry. Why: The crossmember offers adjustable height to preserve proper driveshaft angles in lifted or lowered setups.
Caution: Verify that your specific transmission and mounts align with the crossmember’s mounting pattern to avoid alignment issues.
Kojem Adjustable Transmission Crossmember
The Kojem crossmember targets 1964–1987 Chevy/GMC C10/C20 2WD trucks, Blazers, and Suburbans. It uses high-quality steel and a design suited for lifted or lowered configurations, while ensuring the factory transmission angle remains correct for proper driveshaft alignment. Best for buyers who want a robust crossmember with clear fitment guidance and a focus on maintaining driveline geometry in custom builds.
Who it’s best for: Buyers who need dependable steel construction and clear fitment notes. Why: The design accounts for exhaust clearance with long-tube headers and emphasizes factory-angle maintenance to prevent driveline issues.
Caution: Confirm the product’s fitment against your exact vehicle model year and transmission type before purchase.
ECOTRIC Transmission Crossmember
ECOTRIC’s crossmember is designed for 1973–1987 GM full-size pickups, with powder-coated black finish for durability. It is intended to work with an Energy Suspension performance mount and supports running a 3″ dual exhaust tucked in the frame. Best for builds that pair with performance mounts and dual exhaust configurations without sacrificing crossmember integrity.
Who it’s best for: Builders integrating exhaust routing changes with a crossmember replacement. Why: The crossmember accommodates frame-level exhaust routing while preserving overall driveline geometry.
Caution: This product is most suitable when paired with compatible mounts; verify suspension and exhaust clearance during install.
Buying Guide: Key Considerations For Selecting A Crossmember
Assess compatibility first. Confirm the exact year, model, and transmission type to ensure the crossmember matches the vehicle’s mounting pattern and transmission case. Consider adjustability: a higher range of height adjustment helps accommodate different lifts or lowering setups and improves driveshaft angle control.
Material and finish matter. Look for heavy-duty steel construction and a powder-coated finish to resist corrosion in varied climates and road conditions. If you plan aggressive driving or towing, prioritize thicker end mounts and robust welds.
Ease of installation. Some crossmembers offer bolt-in compatibility with minimal drilling; others may require frame modifications. Evaluate whether you want a product designed for straightforward installation or one that can be adapted for complex builds without extensive fabrication.
Driveline geometry. The primary goal is to preserve or correctly adjust the transmission angle to prevent driveshaft vibrations. Choose models that explicitly mention maintaining factory angles or providing adjustable pins for precise alignment.
Exhaust clearance. For builds with long-tube headers or dual exhaust, verify whether the crossmember supports sufficient clearance or requires additional exhaust routing considerations.
Frequently Asked Questions
- What is a transmission crossmember and why do I need one for an LS swap? It supports and positions the transmission, ensures proper driveshaft alignment, and helps accommodate different engine/transmission combinations.
- Can I install a crossmember on a lifted or lowered GM truck without cutting the frame? Many crossmembers are designed to adjust height without frame cuts, but some applications may require minor modifications. Check the product notes.
- Which crossmember is best for a factory-style build? Models that maintain factory transmission angles and offer straightforward bolt-in installation are ideal for preserving OEM geometry.
- Do these crossmembers work with all GM automatic transmissions? Not all crossmembers support every transmission. Verify compatibility with the intended transmission (Power Glide, TH-350, TH-400, 700R4, LS, etc.).
- Is powder coating necessary? Powder coating provides corrosion resistance and durability, especially in rugged climates or off-road environments.
- Should I hire a professional for installation? For complex builds or high-horsepower setups, professional installation is advisable to ensure precise alignment and safe operation.