1955-57 Chevy LS Engine Mount and Transmission Crossmember

Bolt-in LS motor mount and trans mount solution for tri five Chevy with no welding required
Complete kit with LS engine mounts, transmission crossmember, and hardware
Included mount brackets are made from 7 gauge steel and bolt to inside of frame
LS block adapters are laser cut from 3/8-inch thick steel
Polyurethane motor mounts reduce engine movement and are stronger than rubber mounts
Compatible with stock LS truck (Vortec) truck accessory drive
LS engine location provides sufficient hood clearance to use stock Vortec truck intake
Crossmember fits most modern automatic and manual transmission used in LS swaps
Crossmember made from 1-3/4-inch round steel tubing with .108-inch wall thickness
1/4-inch thick welded end plates and 3/16-inch thick transmission mounting pad
Fits TH350, TH400, 700R4, 4L60E, and 4L80E automatic transmissions
Fits Saginaw 3/4-speed, Muncie 4-speed, and aftermarket Tremec manual transmissions
LS Swap Your Tri-5 Chevy Using Our Bolt-In Motor and Trans Mount Conversion Kit
Chevrolet’s iconic 1955, 1956, and 1957 models, affectionately referred to by enthusiasts as a “Tri-5 Chevy” or “tri five Chevy,” are one of the most recognizable classic cars on the planet. From usage in dozens of movies and TV shows over the decades to magazine project cars like the famed Project X (which itself was also a movie car at one time), their body lines and classic styling work well for everything from straight axle gassers to pro touring builds and everything in between.

We offer thousands of parts to keep your tri five Chevy running and on the road. Now you can repower your tri five Chevy with another iconic part of GM history, the LS engine. No doubt one of the most swapped engine platforms around the globe, powering all manner of hot rods, classics, muscle cars, trucks, and more, the LS swap is a terrific way to keep classic vehicles on the road with performance that will allow modern road speeds and the safety of keeping with today’s traffic flow. Speedway Motors’ tri five LS swap motor mount and transmission crossmember kit is the key to building your tri five LS swap with an ingenious bolt-in solution for your LS engine and transmission.

Thick Steel Motor Mount Supports and Adapters Create a Strong Mounting Solution
Knowing that the LS engine can make some significant power we put some serious thought into how to harness all that power to your tri five’s frame and minimize engine torque movement, so all your LS engine’s power makes it to the rear tires. To facilitate proper engine location for a tri five Chevy LS swap, custom frame brackets are made from heavy 7 gauge steel (that’s roughly 3/16-inch thick) that are located using factory rivet holes in your tri five Chevy’s standard seamed frame (not compatible with seamless frames).

These frame mounts are paired with LS engine block adapters made from laser cut 3/8-inch thick steel that bolt to factory mount holes on your LS block. The frame mounts and LS block adapters are shipped as bare steel, so we suggest paint or powder coating for long lasting protection and appearance. The final piece of the puzzle are our polyurethane small block chevy engine mounts. These are standard small block chevy engine mounts with interlocking safety tongue encased in tough black polyurethane insulator material. Much stronger than stock rubber small block chevy engine mounts yet dampens engine harmonics that a solid steel mount will allow to pass through to the frame and ultimately to you.

Tubular Steel Transmission Crossmember Supports Auto and Manual Transmissions
The original engine and transmission fitted to the tri five Chevy had what some would refer to as “reverse motor mounts” with two mounts straddling the side of the transmission bellhousing area and one mount at the front of the engine. When performing an LS swap to your tri 5 Chevy you not only have to convert to standard side engine mounts, but you need to add a traditional transmission crossmember to your ’55-’57 Chevy’s frame.