Order Status & Returns
Gift Cards
Help Center
1-800-345-4545
Vehicle Info NeededAT-1054 1936-1954 Chevy Bolt-on Transmission Crossmember Top-Hat Frames (4 in. Drop)
Ships on 09/15/2026
Lowest Price Guarantee- 1936-1954 Chevy Bolt-on Transmission Crossmember Top-Hat Frames (4 in. Drop)
Chassis Engineering AT-1054 Features:
Chassis Engineering AT-1054 comes as a Bolt-on Universal Transmission Crossmember with a 4 in. drop, specifically made for 1936-1954 Chevrolet Top Hat-style frames.
This transmission crossmember comes with specially designed frame reinforcement caps to keep stress on the frame sidewall as low as possible.
Chassis Engineering Transmission Crossmember tubes are internally reinforced, heavy duty 1 3/4 in. OD tubing with a 3/16 in. wall.
Don't forget to include a transmission cushion with your order:
SS-0112 for 4 speed, PowerGlide and Turbo 350 transmissions
SS-0114 for Turbo 400 and Turbo 700 transmissions
SS-0212 for Ford C4 transmissions
Note: Requires some fitting to individual frame. Mock-up installation, cut the crossmember tube to length, weld on the mounting flanges and bolt everything in place.
If you prefer, we also offer the AT-1055 Transmission Crossmember for Chevrolet Top-Hat Frames, which mounts underneath the frame for additional clearance.
Installation Instructions for Bolt-on Transmission Crossmember for 1936-1954 Chevrolet Top Hat type frames.
Once original engine and transmission have been removed, remove original transmission crossmember and anything that will interfere with the new crossmember (such as the battery box or apron).
Step 1: Transmission Mounting
Place reinforcing plate over frame and tap into place.
Step 2: Prepare crossmember for cutting by holding it under the frame and marking the excess material.
Remove and cut to length.
Step 3: Place crossmember and flanges in their final position. Tack-weld tube to mounting flanges. We recommend a double-check now with engine and transmission in place. Remove and finish the weld.
4. When sure of spacing, drill all eight 3/8 in. holes through the inside of the frame. If installing with body on frame, outer holes may prove hard to center. Use a sharp center punch thru inner frame to mark outside. The dimple punched in outer frame can then be checked for correct placement. If not correct, punch a new dimple using mark as locating aid. When located properly, drill through the frame from inside out.
5. Bolt transmission crossmember into place. CAUTION: Do not tighten lower bolts to excess. Without tubes welded in the frame, you can buckle sides.
6: Transmission floor cover plate may need to be clearanced to miss transmission.
Chassis Engineering Transmission Crossmembers – Precision Fit Strength For Hot Rod And Custom Builds
Chassis Engineering Transmission Crossmembers are designed to provide durable support, precise drivetrain positioning, and simplified installation for hot rods, street rods, classic cars, and custom chassis applications. Built from high-quality steel construction, these transmission crossmembers deliver exceptional structural integrity while helping reduce drivetrain vibration and maintain proper transmission alignment under demanding driving conditions. Chassis Engineering offers a wide range of universal and vehicle-specific crossmembers compatible with popular GM, Ford, and Chrysler transmissions, making them ideal for restoration projects, performance upgrades, and custom fabrication work. Engineered for easy mounting and long-lasting reliability, Chassis Engineering transmission crossmembers provide the strength, fitment, and professional-quality support needed for dependable street and performance builds.
