LS Transmission Crossmember for F-Body Engine Swaps
When dropping an LS powerplant into a classic F Body chassis, the 1970 to 1981 F Body Sure Fit crossmember streamlines the swap by securing the transmission and engine to stock frame mounts without cutting or welding. Built from heavy gauge steel and designed to fit both 4L60E and 4L80E units, this crossmember maintains correct engine angle and resists twisting under spirited street or track loads to protect driveline components. Installers appreciate the precise alignment with factory frame rail holes, which preserves driveline geometry, limits wear on U joints and driveshaft bearings and avoids custom bracket fabrication or floor pan alterations.
Precision Engine and Transmission Alignment
The crossmember's form is engineered to match the original frame rails of 1970 to 1981 F Body models, ensuring the LS engine and 4L60E or 4L80E transmission sit at the factory intended angle. By anchoring directly to the stock mounting points, it preserves proper driveline geometry and keeps the driveshaft centerline aligned under all load conditions. Correct alignment minimizes vibration and NVH transmitted into the cabin, while also reducing stress on U joints and carrier bearings for longer service intervals. Installers benefit from a solution that replicates factory dimensions without the need for guesswork or trial fitting. The result is smooth power delivery and consistent handling whether cruising on the street or pushing hard on the track.
Heavy Gauge Steel Construction for Rigidity and Durability
Manufactured from thick rolled steel plate, this crossmember resists twisting forces that occur during high torque launches and spirited cornering. The robust material choice prevents the chassis from flexing under load and safeguards the connection between transmission and frame rails. In hard use scenarios the component exhibits minimal deflection, protecting mount bolts and weld seams from fatigue. The stout construction also helps maintain consistent driveline angles, keeping vibration and premature component failure to a minimum. Overall, the design provides a stable foundation for high output LS engines over thousands of miles of demanding driving.
Simplified Installation with Direct Frame Compatibility
All mounting holes are pre-punched to match the factory frame rail patterns, allowing the crossmember to install with original fasteners or the supplied hardware. This drop in solution eliminates cutting, welding or bracket fabrication and preserves the vehicle's underbody structure. Clear, step by step instructions guide the installer through proper torque values and bolt sequence, ensuring reliable repeatability on any build. The result is a clean installation that maintains factory clearances around exhaust components, fuel lines and brake plumbing. Technicians appreciate the time savings and the absence of sheet metal trimming or adaptation work.
Professional Grade Manufacturing in the USA
Produced under strict quality control protocols, this crossmember bears the mark of American craftsmanship from raw material through final inspect. Welding is performed to precise standards to deliver consistent strength and fitment across every unit. Although it ships bare, the heavy gauge steel surface is prepared to accept paint or corrosion resist treatment for long term protection. Components are assembled and checked for dimensional accuracy before they leave the factory, giving builders confidence in fit and function. Backed by a commitment to domestic production, owners know they are installing a product designed and built to meet rigorous performance expectations.
This crossmember delivers precise alignment and durable support for LS swaps. To complement your Related CRS product see our 3rd Gen F-Body Crossmember (Only) 4L60E.