Product Summary

Chevy LS V8, Adapter Mount Motor Mount Type, Natural

  • Easily install a modern LS engine into your Tri-5 with this complete bolt-on motor mount set
  • No welding required – frame brackets are installed by removing two rivets and drilling two holes on each side of the frame
  • Engine location is set by the two factory rivet holes which ensures your engine will fit the first time with no mock up or test fitting required
  • Includes LS engine adapter plates, polyurethane motor mounts, frame brackets, and hardware
  • Detailed instructions with photos and diagrams are included to assist with installation

Key Specs

MFG. Part #91655571
BrandSpeedway Motors
Mount MaterialSteel/Polyurethane

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  • Bolt-in LS motor mount solution for ’55, ’56, and ’57 Chevy with no welding required
  • Included frame 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
  • Complete kit with LS adapter plates, polyurethane mounts, frame brackets, and hardware
  • Compatible with stock LS truck (Vortec) truck accessory drive
  • LS engine location provides sufficient hood clearance to use stock Vortec truck intake
  • Not compatible with tri five Chevy models with seamless frame assembly

LS Swap Your Tri-5 Chevy Using Our Bolt-In 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 kit is the key to building your tri five LS swap with an ingenious bolt-in bracket kit.

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.

All You Need Are Basic Hand Tools to Add Modern LS Power To Your Tri-5 Chevy

We designed our tri five LS motor mounts for ’55-’57 Chevy LS swap to be easy to install. The frame mount installs on the side of the frame after you grind/drill out a pair of frame rivets on each side and then use the mount as a template to drill a pair of additional holes. Once this small modification is complete everything else in our tri five LS motor mounts kit bolts together with the included hardware. There is no need to mock up engine placement, as we’ve done all the challenging work for you. Once the frame mounts are installed to the frame and the adapters and SBC motor mounts to your LS block your LS engine can be lowered into place.

Depending upon the LS engine being used you may need to update your LS with a low profile oil pan to provide enough crossmember clearance. Then you’re ready to move on with your LS swap using our bolt in transmission crossmember, LS swap headers and more. Fall in love with your tri five Chevy all over again with modern LS power under hood.



MFG. Part #91655571
BrandSpeedway Motors
Mount MaterialSteel/Polyurethane
Motor Mount TypeAdapter Mount
Application CompatibilityEngine Swap
Attachment StyleBolt-on
Mount FinishNatural
Adapter MaterialSteel
Adapter FinishNatural
Hardware IncludedYes
Sold in QuantitySet
NotesNot compatible with seamless style frame