C6 Corvette 5.3 Truck Motor LS Swap: Blasphemy or Budget Brilliance?

A C6 Corvette Grand Sport owner doing a 5.3 truck motor LS swap? To replace an LS3? …The purists are furious.

Over the years, the Chevrolet Corvette has traditionally been equipped with General Motors’ strongest V8 engines of the era. That is why we generally don’t see many engine swaps projects, especially when talking about newer Corvettes. While engine-swapping a Corvette is relatively unusual, an owner performing a 5.3 truck motor LS swap is practically unheard of.

However, that is exactly what “V8sten” is doing with his C6 Corvette Centennial Edition Grand Sport.

After the factory LS3 expired, the OP wanted to get this Corvette back on the road, but he didn’t want to spend a ton of money. Buying an LS3 would be expensive, so instead, he went the route of so many people who wanted an inexpensive LS-swap. He purchased a heavily used LC9, which measures just 5.3-liters and he is rebuilding this smaller engine to replace the LS3.

As you might imagine, some folks within the Corvette world are unhappy with the decision.

Corvette LC9 Swap Introduction

When the OP introduced the community to his 2012 Corvette Centennial Edition Grand Sport project, he simply started with the following.

The LS3 blew up so this is happening………”

That was followed by a picture of two LS-based engines sitting side-by-side on engine stands with the caption “Blown up LS3 in the rear, LC9 5.3 replacement

He then shared an array of pictures of the LC9 before and after he cleaned it up. It has clearly seen many miles, but that really doesn’t matter when you plan to rebuild. What does matter to the community is the fact that he is swapping a small truck engine into a special edition C6 Corvette.

For those who aren’t aware, the LC9 is a 5.3-liter V8 in the LS engine family. It was utilized in GM trucks and large SUVs from 2007 through 2014, offering as much as 320 horsepower and 335 lb-ft of torque. GM sold a ton of vehicles with this engine, so they are plentiful in salvage yards. They are also relatively inexpensive, making the 5.3 truck motor LS swap one of the most popular options for a cheap LS-swap project. That is why the OP chose this engine, as his goal was to get the Grand Sport back on the road without spending much money.

Community Questions the Move

The first member to question swapping an LC9 into a 2012 Corvette Centennial Edition Grand Sport was “Fauee”.

Uhhh, gonna ask… Why? There’s plenty of truck 6.0 and 6.2s out there, why a 5.3?

To which the OP replied with the following.

So far I have a little over $1000 in this entire project. It should be in the 11s when I get it running. Plus I plan on boosting it later. I have all the wet sump stuff coming in the mail, which I would of have to of gotten anyways.

Next, “Jbc1995fb” asked why he didn’t just fix the LS3.

So I’m asking this question with all respect. I’m not a mechanic, but I’m guessing the original engine block was not rebuildable?

what ever you’re doing to the 5.3 engine, couldn’t you put same amount of time and effort into rebuilding a 6.2?

So the OP explained why he didn’t just fix the LS3.

The LS3 will need to be sleeved, If Im going to do that, its getting Darton 4.125 sleeves. That is not in the budget right now. In the meantime a cheap 5.3 will do. I may spray a 200 shot, I may build a TT kit. Only the future will tell. But one thing is for certain, not many f#cks will be given towards this 5.3. Plus this 5.3 is supposedly the strongest casting aluminum block GM made.

Fauee posted again, providing some insight on LS engines and explaining why he doesn’t care for the project.

If you’re gonna go 5.3, you want one like in my Colorado. An lh9 is the aluminum 5.3 with the stupid afm stuff that craps out. Plus you get vvt and such, but they’re only 300hp stock.

If you’re wanting to boost it, I guess it makes sense. But then if you want to boost it you’d be better with the iron block.

I have to agree, I’d just fix the LS3. Seems like a waste of a great car to do some weird 5.3 build. That sounds like a build for a c5 or a camaro, not a centennial GS. Just my opinion though, your car your choice and I’m sure it’ll be fun.

That led the OP to once again defend his choice.

The LC9 had VVTand DOD, all that is in the recycle bucket now. In the end, my car, my money. Its better than the car sitting in my shop. At least I can drive it with this cheap @$$ motor.

Current Progress

In the first post in the thread, the OP showed us the LC9 during the build process. He also shared the LS2 intake manifold that he will be using along with various engine shots. Unfortunately, his progress was halted when he learned that the camshaft was too big and the valves were hitting the pistons.

He tried to add small valve relief notches, but they weren’t sufficient. As a result, he pulled the bottom end and sent the pistons to a machine shop.

Pistons are off to the machine shop to have valve reliefs cut into them. Gunna gap the rings too. Its a good thing i took it apart. The previous owner failed to tell me that the front two rod caps were removed. It would of spun those rod bearings.

That appears to be where the project has stalled for the moment, but we can’t wait to see what the OP does with this car once the engine is put back together. With talk of a big nitrous setup or turbocharging, this  5.3 truck motor LS swap is about to live a very exciting new life.

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