Old Guy’s Advice on an LS Conversion

LS Swap

It all boils down to what your specific aims are in making an LS swap and how much you want to spend when it comes to selecting an engine.


 A junk yard 5.3 or 6.0 is the engine to switch for most people. They normally cost between $500 and $1,500, with just a cam swap, you can create respectable power.


The all-aluminum LS1 engine is the next step up in price. This engine will normally cost around $2500 when complete with all accessories.

The next level up are LS3 and LS7 engine versions. The LS3 was the most powerful Corvette engine to date when it debuted in the 2008 Corvette. The LS7 is the largest LS engine and is hand-built at the GM Performance Build Center in Michigan. It produces more horsepower than the LS3. These engines range in price from $6000 to $15000.


A successful LS transplant starts with the motor mount adapter plates. Adapter plates attach to the LS engine block and allow the engine to be firmly bolted to the vehicle.

Keep in mind that the mating point for an LS engine is closer to the transmission than the mating point for an SBC engine while mounting the engine. Due to firewall clearance concerns with the passenger side cylinder head, most automobile applications need the LS engine to be shifted forward.


If you wish to keep your low-mount AC compressor. You are free to keep your factory-installed low-mount AC compressor. No adapter plates on the market, however, will fit adequately. You’ll need to notch the frame to make the stock low-mount AC compressor fit.

This is due to the fact that the LS AC compressor and bracket are positioned immediately in front of your stock crossmember. This is true for all GM vehicle applications. A welder and a cut-off wheel will be needed to notch the crossmember.


After you’ve decided which LS engine to use for the LS engine swap, you’ll need to decide which transmission to use behind it.

Some folks prefer the earlier GM transmissions, such as the TH350, TH400, or 700R4. These are viable options from a financial standpoint. However, to work with the LS series flexplate, these transmissions require a flexplate adapter.


We strongly suggest the GM 4L60E transmission over a regular three-speed automatic transmission. To match the pricing range, the 4L60E transmission gives a great driving experience.

If your budget allows, the GM transmissions 4L80E and 6L80E are also excellent options. Unless you have a performance built engine, they are usually unnecessary.

All of these transmissions are easily available from a nearby salvage yard.


The T56 or TR6060 transmissions are recommended for people who wish to thrash through the gears for a thrilling driving experience. Either of these gearboxes can readily bolt up to any LS engine with the necessary flywheel and clutch.

The TKO500 and TKO600 transmissions are also common choices. Many carbureted cars have been modified to these new 5-speed transmissions; however the input shaft does not reach the crank. Simply replace the old bellhousing with the GM 621 bellhousing to get around this. A pilot bushing and an LS flywheel are also required). This flywheel is.400 inch thicker than the regular LS flywheel, compensating for the fact that the LS crank is.400 inch further behind the bellhousing.

For installing the hydraulic master cylinder to the firewall beneath the brake booster, there are numerous methods to set up your hydraulic clutch system, however the following examples will get you started in the correct direction:

An adapter bracket for the hydraulic master cylinder or, a complete kit with master cylinder is available.


When it comes to your LS swap, flex plates may or may not be an issue. There will be no issues if you use a current transmission. A simple LS flexplate will suffice.

You may still use the LS flexplate to mate an older transmission, such as the TH350 or TH400, but you’ll need a flexplate spacer. The torque converter hub will be supported by the flexplate spacer, which will align it with the crank.


The accessory drive is responsible for propelling the accessories that act in conjunction with the engine.

When it comes to selecting an accessory drive for your LS swap, there is no “one size fits all” solution. You’ll need to perform some more research about your exact LS swap application, as well as what will meet your demands.

There are three main layouts for auxiliary drive spacing. Spacing for the Corvette, Camaro, and Truck/2010+Camaro.

The Corvette spacing is the closest to the engine block, whereas the Camaro spacing is 3/4 inch distant. The Truck/2010+ Camaro spacing is 1.5 inches wider than the Corvette’s.

These supplementary drives are sold by a number of firms, both factory and aftermarket. There is no such thing as a “one-size-fits-all” solution; you must research your specific swap application to discover which method is ideal for you.


The engine wiring harness is a crucial part of your LS conversion. It may appear frightening to some, but it is actually rather basic and clear. When performing an LS swap, you have three choices for successfully integrating the engine wiring harness. You have the option of purchasing a standalone harness, having a new harness custom constructed, or rewiring the harness that came with your LS engine. The harness that came with your LS engine will almost always need to be rewired. This is a cost-effective solution that may be completed quickly by a professional who is familiar with these harnesses.

Though it may be tempting to handle the wiring for the harness yourself to save money, we strongly advise having the rewire service done by a professional unless you have prior experience with proper wiring techniques.

If you insist on tackling this task on your own, make sure you complete your homework. On YouTube, you can discover several useful tutorials to guide you through the process.


Different oil pan applications are necessary for cars and trucks due to the clearance.


There are various vendor possibilities for automotive applications; many are hit or miss in terms of quality and fitment. Do not make any concessions in either area.


Truck oil pans are a little easier to work with because most standard truck oil pans will fit into most historic truck applications. They do, however, dangle a little lower than the factory pan, but this is easily remedied. If you’re looking for a specific recommendation, considerthe Hummer H3 oil pan because it works well on all truck applications.


The steam tubes on the engine are the tubes at the top of the heads. By enabling hot regions to clear and escape, they prevent the heads from overheating. They’re important, so don’t close them until you’ve bled out all of the air in the coolant system. If there is any air left in the system, capping them off will cause problems down the road, causing hot spots at the tops of cylinders 1 and 2.

When conducting the LS replacement, make sure the tubes are connected in a way that allows the air to exit safely. The steam tubes can be connected to the water pump spacers or the water pump housing, or they can be connected to the radiator.

You can run your steam line right into the spacers if you’re using water pump spacers. Another option is to drill a 1/8 barb fitting into the top of your water pump housing and connect it there.

You can either run a line into the top radiator hose or drill into the radiator’s high point and connect there.


Because your gauges provide important information about what’s going on within the car, you’ll want to pick themcarefully and install them correctly when conducting an LS swap.


You can utilize a factory speedometer if you’re utilizing an older transmission. If you have a modern transmission, you’ll need a gear housing that can accommodate a mechanical speedometer.

Another way to ensure speedometer compatibility is to run a mechanical speedometer wire to the transmission through a Cable X. Your transmission’s Vehicle Speed Sensor (VSS) will be converted by the Cable X to properly drive the cable.


There are various aftermarket producers of electronic gauges and senders. You may wire these electronic gauges and senders into your LS wiring harness.


When completing an LS swap, the most typical way is to use a C5 Corvette fuel pressure regulator in conjunction with a high-flow electric fuel pump. With this combination, most people use fitting adapters. You’ll also need a gasoline line that’s rated for fuel injection.. The system needs continuous pressure to work in a fuel injection setup.

Your engine will die if there is no baffle in your tank and the fuel moves away from the pickup tube when you corner. However, this is usually just an issue if your tank is less than 15 percent full.

External pumps can be used, although an intake pump with correct baffling is suggested to minimize fuel starvation when cornering with a low gas tank. With a carburetor, this is not an issue because the bowls are large enough to protect the engine from running out of fuel.


When it comes to exhaust, the variations and alternatives are endless. You should anticipate that no exhaust system will fit perfectly right out of the box. Depending on the car’s present exhaust system, you’ll need to have your original pipes stretched or shortened at the very least.

Switching to headers will increase top-end horsepower while keeping the factory LS manifolds will keep low-end torque.

Headers do a fantastic job of waking up an LS engine while also sounding fantastic. Many large header manufacturers now make swap headers because this has become a popular swap.

The factory manifolds are an excellent alternative if you want to keep things quiet and aren’t concerned with getting the most horsepower possible. The majority of manufacturing manifolds will work in any situation.


You’ll need a carburetor LS intake manifold if you’ve decided to go with a carbureted configuration. There are numerous alternatives to choose from.

If you’re switching to a carburetor, you can get rid of the valley cover’s knock sensors and wiring. A control box is required to run the ignition system on an LS engine because there is no provision for a distributor.

In the long run, LS swaps will save you a lot of money in terms of fuel mileage. In comparison to an SBC platform, they will also give improved drivability and reliability.