Product Summary

  • Compatible with all LS engine bolt-ons such as intake manifolds, headers, oil pan, timing cover, water pump, and accessory brackets which makes positioning or fabricating engine mounts a breeze
  • Weighing in at 18 pounds for the short block or 35 pounds for the long block, this LS mock up engine can be lifted in and out of the vehicle by one person without the need for an engine hoist
  • Replicates all Gen 3 and Gen 4 LS block size for test fit of LS1, LS2, LS3, LS6, LS7, LSA, and Vortec truck engines 4.8L, 5.3L, 6.0L and 6.2L
  • Heavy duty 12 gauge steel construction is designed to last unlike the LS foam block which often suffers damage from thread inserts pulling out of the foam core
  • Long block version comes with bolt on fabricated steel mock up heads | Short block version accepts all factory and aftermarket LS heads

Key Specs

MFG. Part #
BrandSpeedway Motors

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  • 12-gauge steel construction is strong, durable, and lasts unlike foam/plastic versions
  • Accepts all LS bolt-on parts (exhaust, intake, oil pan, etc.) to confirm engine fit
  • Available in short block and long block mock up engine configuration
  • Short block version weighs 18 pounds and accepts stock or aftermarket LS cylinder heads
  • Long block version weighs 35 pounds and includes steel fabricated mock up heads
  • Complete long block weighs only 6 pounds more than popular foam versions
  • Easily lifted and set into place by hand without engine hoists or additional help
  • Can be used to mock up any LS engine, including LS car and Vortec truck engines
  • Crankshaft pulley spacing dimensions laser etched on front face for quick visual access
  • Long block cylinder head mock up panels are adjustable for standard LS vs LS7 heights
  • Ships and can be stored flat with simple assembly/disassembly steps
  • All hardware included for assembly of short or long block versions
  • Customer supplied head bolts and accessory bolts required to add parts to mock up

Test Fit Your LS Swap Quicky and Easily Without the Need for An Actual Engine

LS engine swaps are THE thing these days. We’re seeing them in everything from traditional first gen Chevy V8 applications like classic Camaros and Chevelles, to imaginative installations in Porsche 911s, the Tesla Model S, and much more. While those first gen Chevy V8 fitments are the easiest with the installation only requiring engine swap mount adapters, it is still beneficial to have the LS engine in place for mocking up everything from air induction tubing to custom header fabrication, and more. It is even more critical for those crazy one-off swaps to have a block in place to confirm driveline angle when using custom weld-in mounts, engine placement to clear the radiator and firewall, and more.

Traditionally, building something with an engine that was never meant to be installed in it would require an engine hoist, an actual engine, and a spotter or two keeping things in check while measurements were taken, parts tack welded, and so forth. It’s not an easy or quick process, and it can be dangerous with a 400 plus pound engine dangling on a chain over your hands (or head!). Though “this is the way” may work for the Mandalorian, for us here on Earth there is a better way, and that is with the Speedway Motors steel LS mock up engine block. 

Laser Cut Steel Plate for Strength, Simplicity, and Easy Storage

Even if you have your LS engine all apart down to the bare block, that bare casting is still a couple of hundred pounds to try and roughly move into place to figure out your engine mounts, headers, and more on your project. Using replica engines to mock up your LS swap for your project is much safer and your back will thank you for your efforts.

Past mock up options included a plastic engine block or foam engine block, which, while being light and easy to maneuver, these plastic engines often did not hold up well to repeated usage or the installation of heavy components like long tube headers. This is why we designed our LS mock up block system from laser cut 12-gauge steel with all accessory mounting holes accessible from the back side for simple “nut and bolt” assembly of your accessories for engine mock up. No more thread inserts that work their way out of the foam engine block material or even needing the factory hardware during the mock up phase. Just grab yourself any fastener of the proper length and diameter, saving the good installation hardware for final assembly.

Furthermore, our LS engine mock up block, which is available in short block and long block options, ships unassembled, saving you shipping costs and storage room when not in use. Simply assemble the mock up pieces following the provided instructions with the fasteners included and your mock up engine block is ready to use in minutes. Disassemble it for storage where it will easily fit under a workbench, on a shelf or other location that a full size plastic engine block or real engine block wouldn’t fit or have the weight capacity to handle (ever try storing a real engine block on a plastic shelf?).

Our steel LS mock up block weighs in at just 18 pounds for the short block and 35 pounds for the long block (that’s only six pounds heavier than the foam engine block version we mentioned), making it easy to handle and position all by yourself safely in the engine bay of your project. If you opt for the long block version the included 12-gauge steel cylinder heads provide mounting locations for your intake manifold, exhaust manifolds or headers, and even your valve covers.

This allows the complete mockup of an assembled and dressed engine, right down to ignition coils and more to confirm fitment, clearances, plumbing and wire routing, and so much more easily. Even if you’re just using the short block, you can confirm fitment and engine location by mounting an LS swap oil pan, timing cover, water pump, and accessory brackets to our mock up block easily. The short block also accepts all stock and aftermarket LS cylinder heads as well, so feel free to bolt up your actual cylinder heads for your mock up duties if you like!

Replicates All LS Engine Platforms to Mock Up Fitment of Any LS Engine

We did all the homework for you when designing our new steel LS mock up engine block assembly. We have provided all mounting holes to replicate the engine block and heads of all Gen III and Gen IV LS engines. Whether it is the original LS1 or you’re planning for an LS6 or LS7, or perhaps you scored a Vortec series truck engine on the cheap, no matter what LS series or generation it is our steel mock up block system will work for your mock up needs.

Due to the variances in LS platforms, there are differences in the accessory drive spacing. There are three different spacing dimensions (measured from the front of the block) and you need to adhere to these measurements when choosing which accessory drive you are planning to use, especially if you’re keeping the factory components from a used engine or a crate engine that is using stock components. Therefore, we made it easy on you by simply engraving these dimensions right on the front face of the mock up engine block.

Now you can quickly and easily confirm you have enough clearance to radiator cooling fans, power steering rack, fluid reservoirs, and other items commonly found at the front of the engine compartment. Note that we offer adjustable LS engine mount brackets that can move the engine up to 3-inches total adjustment fore and aft to assist with accessory drive clearance.

So, whether you plan for a sole LS swap in your home garage, or your hot rod shop is looking for an easier way to make LS swaps happen in your customer’s cars, our bolt together steel LS mock up engine block will help you get the job done safely and quickly.


See our LS Swap Guide for more tips and info on making your LS swap project a success!

Not sure if your LS is a Gen III or Gen IV, Our LS ID Guide will help you determine just what you have!


MFG. Part #
BrandSpeedway Motors
Material TypeSteel
Sold in QuantityKit