LS and LT Transmission Crossmember for GM B-Body Models
Swapping an LS or LT engine into a 1965 to 1970 Impala or Caprice frame often turns into a geometry puzzle if you stick with the stock crossmember. This LS and LT transmission crossmember removes the guesswork by using factory mounting points to hold the transmission at the exact height and setback specified by GM. Crafted from thick steel plate contoured to each B-Body frame rail, it not only preserves driveshaft alignment but also stiffens the chassis for more consistent handling under load. Whether you are installing a popular 700R4 automatic or a manual gearbox, this crossmember delivers precise support and fit without any cutting or welding.
Precision Engineered for LS and LT Driveshaft Geometry
The crossmember uses factory frame rail mounting points to secure the transmission at the exact height and setback GM specified for LS and LT powerplants. By holding the tail housing flange at the correct angle, it minimizes vibration and universal joint wear, which in turn extends the life of driveline components. This precise geometry ensures smooth torque transfer to the differential and delivers a quieter cabin experience under both cruise and spirited acceleration. Installers benefit from predictable alignment without the need for trial fittings or shims.
Seamless Bolt In Fitment for 1965 to 1970 B-Body Frames
Designed to drop directly into existing holes on Impala and Caprice chassis, this transmission crossmember eliminates cutting, drilling, or fabrication. Even first-time builders can position the unit using standard hand tools, following GM's original bolt pattern for effortless installation. The straightforward process frees up time normally spent measuring and adjusting, yet maintains the structural interface found in the stock design. As a result, the swap moves ahead with minimal fuss and keeps service bays clear of extra brackets or adapters.
Reinforced Steel Construction Boosting Chassis Rigidity
Formed from thick, high grade steel plate contoured to each frame rail, the crossmember resists bending under heavy load transitions and repeated acceleration. Critical weld seams are strategically placed at stress points to spread forces evenly along the rail, preventing fatigue and deformation. This robust construction not only safeguards the transmission mount but also stiffens the surrounding frame area. Enthusiasts will detect sharper turn-in response and a more planted feel when pushing the chassis under load.
Transmission Flexibility with Common GM Gearboxes
Whether fitting a 700R4, 4L60, TH350 automatic or a manual transmission, this crossmember accommodates popular bellhousing patterns without adapter plates. Tailshaft clearance and mount spacing align perfectly with the most widely used GM units, giving builders the freedom to choose their preferred driveline. By removing the guesswork around offset and height, it streamlines project planning and speeds up mock-up stages. The result is a consistent, reliable power path from LS or LT engine to rear axle in virtually any combination.
Count on MuscleRods for precise LS and LT swap support and see our related CRS product 1958-1964 B-Body Sure-Fit Crossmember (Only).