The term “budget” has different meanings for different people. To some this might be the amount of money you set aside each month for bills or the amount of money you have to buy a car. Having a financial budget is almost a necessity in all aspects of life, from your personal check book to running multi-billion dollar corporations. For most, the term budget refers to watching your bottom dollar or “as cheap as possible.”
We like shiny new car parts, and have to have them sometimes, even when it’s out of budget. This means our engine builds don’t always adhere to the low-cost budget mentality, even when we want them to.
Based on the LS engine, this 6.0-liter truck engine was designed to bridge the gap between the new LS small-blocks and big-blocks for the truck applications. The major difference in the LQ4 engine is that they are cast iron instead of aluminum. Bolting a set of LS6 heads to the iron block, the LQ4 was born. The 1999 and 2000 model year engines had cast iron heads with all other model years sporting the cast aluminum heads. The beefy iron block and the 4.000-inch cylinder bores that can accommodate the GM L92 heads make for some serious horsepower at budget prices. For junkyard engine builds, this is a very desirable engine. The LQ4 and LQ9 are the most common Gen III LS blocks, and are very desirable due to the big bore and durable iron construction. Some have made 1,500 horsepower on this block. All trucks manufactured with Gen III & IV engines have a serial anti-theft system. This serial anti-theft system is only defeatable through ECM reprogramming. You should plan on having the ECM re-flashed when installing this into your transplant vehicle.
- Displacement: 366ci
- Block: Cast Iron
- Heads: Cast Aluminum or Cast Iron 15-degree cathedral port
- Compression: 9.4:1
- Bore & Stroke: 4.000-in x 3.622-in
- Specs: Rated at 300 horsepower to 325 horsepower and 360 lb-ft to 370 lb-ft from the factory.
- Where to look: 1999-2004: Chevrolet Express/GMC Savana, Chevrolet Silverado 2500, Chevrolet Suburban/GMC Yukon XL Denali, Hummer H2.
Our first step for the swap was figuring out what LS engine to go with. There are numerous different configurations so we referenced our Junkyard LS Engine Builds: Going From Rags To Riches article to help decipher the options.
We knew that we wanted an LS that would be cheap, but we also wanted decent power. The 4.8-liter LS engines are super cheap and plentiful, but lack in the horsepower department. 6.2-liter supercharged LS engines have more than enough power, but the price for one of those was outside of our financial range. A basic LS1 still demands a pretty penny with their proven performance and popularity. We had to stick to our guns on this one and maintain going the cheaper route.
After reading the Junkyard LS article, we went with the “Junkyard Special,” which is the LQ4 engine. The LQ4 is a 6.0-liter LS, with a steel block. These are on the lower end of the pricing scale, as most people are looking for all-aluminum engines. With six liters, or roughly 366 cubic-inches, the engine will have plenty of horsepower and torque to move any car. The stronger steel block will also handle power adders better than the aluminum version, and will happily accept upgrades later on down the road.
With our decision made to use the LQ4 engine, the hard part came about when trying to source one. We could have gone to a junkyard and spent hours searching and hopefully finding an engine, but around these parts, LS engines get picked up within an hour of the vehicle being set out to pasture. Even if we did find what we were looking for, we would have to pull the engine and hope that it was in decent shape, and not need a rebuild.
Time is money for us, so we decided to pick up a complete junkyard engine that had already been tested, pulled, and comes with a warranty. This saves us hours, if not days,and more importantly-headaches.
“We go a step further, and make a video of the truck running so you can hear it run and see the vitals on the gauges before pulling it out of the truck.”-Stu, Just Chevy Trucks
Another great feature of Just Chevy Trucks is the motor is 100 percent complete, including the wiring, sensors, accessories, and everything else on the engine. Buying an aftermarket harness and all of the accessories could add up quick and blow our budget. Lastly, they offered to convert the wiring harness as a stand alone harness. They added in an OBD-II connector, along with a fuse panel to power the engine.
Just Chevy Trucks is roughly 3,000 miles from us in sunny southern California. We would have to pay for shipping, but we wanted to show that even though the engine isn’t local to us they can still be had on a budget. They looked in their inventory and found a great LQ4, with only 170,000 miles on the clock. The best part, was they have a video of it running, before pulling:
After hearing the engine run and seeing that it wasn’t overheating and had good oil pressure, we knew we had the right engine. But we needed a transmission as well. The transmission that was bolted to this LQ4 tested well, but we opted to have it rebuilt to ensure another 100,000+ miles of carefree shifting. The 4L80E that was bolted to this engine was picked up after being rebuilt by Dr. Steve’s Transmission Clinic. With the drive train package complete, they put them on a crate and shipped them out to us.
When the time came to swap the engine and transmission into our car, there was a list of things that we needed to consider: motor mounts, radiator and hoses, wiring and computer, transmission and mount, exhaust, oil pan, fuel delivery, and driveshaft modifications. Depending on what car you’re putting the engine in, skill level and budget, there are a lot of options for each one. First things first, we had to get the engine and transmission into the car to see how they fit, so let’s take a look at motor mounts and what route we took to stay within budget.
Unfortunately LS engines don’t just simply bolt in place of a traditional small-block or big-block. While they are similar in size, the engine mounts are different. With the ever growing popularity of swapping LS engines into classics, there are a lot of options for engine mounts. If you’re wrenching a more popular car, such as 1969 Camaro, there are numerous companies making “bolt-in” kits. Since our car isn’t “popular,” we would have to figure it out and fabricate mounts ourselves. There are several companies that make conversion plates as well, so you can utilize a traditional small-block engine mount in place of the LS engine mount.
We had several options to choose from for our car. What we did was went part’s hunting in a buddy’s garage. We found a set of LS to SBC plate adapters along with a set of SBC motor mounts. These were free, and much smaller than the LS motor mounts that came on the engine. To make the frame horns we sacrificed a pair of frame mounts from a Chevelle. With a lot of measuring and a little bit of welding we had the engine sitting nicely in the engine compartment.
This is one of the most crucial parts when swapping in an LS engine. You need to check for clearance and fitment with all parts of the engine, the drivetrain, the serpentine system, even hood clearance. Getting the engine in this spot was by far the most time consuming part of the swap, but saved us hours of headaches later.
Every radiator is going to be different for every application, but this is something to consider. LS engines, depending on the year, had either the outlets opposing each other in a traditional fashion, or on the same side of the radiator. We could have called up a radiator company and had them custom make one specific for this car. However, sticking to our budget we hopped on Craigslist and found a complete radiator with dual fans from an LS powered fourth-gen Camaro for $60. This required us to cut and reweld the factory radiator mounts, but no big deal there. Within an hour, we had the cooling system squared away. The last step was to order some new hoses, which fit nicely.
We didn’t get as lucky as we thought. After getting the engine running, one of the plastic tanks on the radiator cracked. We were forced to buy a new radiator from our local auto parts store. Luckily these are only $100 new, and readily available. The Craigslist set up was still worth it for the cost of the fans alone.
Since we’re running the 4L80E which requires a transmission cooler, we had to figure that out. The radiator we are using has a cooler, but digging around the garage we found a B&M transmission cooler, so we decided to use both. The fluid runs through the radiator, then through the external B&M cooler, then back to the transmission. We plumbed all of it with extra AN fittings and hose that we had after plumbing the fuel system.
Wiring up an LS engine is something that could scare a lot of people. Have no fear though, as there are a lot of companies that make LS wiring harnesses for conversions. They can build or modify a harness to your specifications by omitting secondary O2 sensors, Vehicle Anti-Theft Systems, and/or tuning the computer for a non-stock engine.
Since we are keeping this engine stock, we utilized the stock harness and used the stock computer. Just Chevy Trucks converted the harness for us, removing unnecessary items, and flashing the computer for those changes. They also added a fuse panel and OBD-II connector. This factory wiring harness isn’t the fanciest, but it works flawlessly and was simple to wire in.
The alternator and the battery cable to the starter were the only wires that had to be connected from the converted wiring harness. They were all clearly marked, making an easy installation. These were wires such as: hot, hot in run, starter signal, tach, etc. Attaching them only took an hour or so.
Looking again at the cost of picking up a wiring harness versus spending countless hours on it ourselves, we opted to have Just Chevy Trucks convert it for us and include the wiring with the engine.
Transmission and Driveshaft
You could use a traditional GM transmission, such as a 7ooR4, TH400, or a manual but since the 4L80E we’re using is much bigger than what came out of the car, we did have to cut and rebuild the transmission hump.
As far as mounting the transmission we used the stock 4L80E rubber mount and fabricated a perch for it to sit on the stock crossmember. In order to get the car shifting properly we called Lokar Performance and got a universal column shifter kit. This allowed us to use the factory column shift. This was money well spent as the installation of the Lokar shifter only took about an hour total.
If you use your existing transmission, the driveshaft can stay. However, if you’re swapping transmissions or the mounting location of the transmission, you might have to have the driveshaft lengthened or shortened depending on your application. In our case, the engine and transmission were set further back than the original.
To make matters worse, the car has a two piece driveshaft. We could have opted to have the front shaft shortened, but we didn’t want to take any chances here. We ponied up, gave the experts at Inland Empire Driveline a call, and had a new driveshaft made. This ensures a perfect fit and no vibration cruising down the road. Even hopping on the freeway doing 75 mph, the car has zero vibrations.
Just like the other parts, there are many options for an exhaust. Many header companies are now making LS conversion headers to fit in classic cars. If your car is unusual you might have to test fit and see what works. You could utilize the factory manifolds as well, assuming they fit. Some people have had great luck in using the cast-iron Camaro manifolds, as they are tight to the block, and rear exiting. What you use depends on your budget and space available.
Since we were on a budget, we were determined to keep the cast-factory manifolds. This took a little massaging of the frame for clearance on the passenger side. The driver’s side is where we ran into a lot of problems. Mainly, the rag joint that connects the steering column to the gear box. It was way too big. Luckily, Borgeson makes a steel coupler that dramatically reduced the size. This, along with grinding off of a boss on the manifold allowed the stock manifolds to clear. From here, we had a local muffler shop weld up the exhaust pipes to connect from the manifolds, to the rest of the stock exhaust.
Besides the motor mounts, one of the biggest concerns is the oil pan. Some LS engines have a very deep oil pan that won’t work in a lowered car. Cross member placement along with steering linkage is all going to factor into the equation as well. Several companies make pans that are low profile and designed to work around cross members and suspension. Again, this all depends on your application. Make sure to pay attention to where your cross member is, and if the steering components are in the front or rear of that cross member as these will affect which pan you use.
In this case, the factory truck pan fit perfectly. It cleared the front cross member, and the steering linkage. However, when we looked under the car, it was hanging down just waiting to get clipped on a speed bump. We were on a budget, but had to get an oil pan that tucked up nicely to give us plenty of ground clearance. We thought about cutting and welding the original, but figured we’d need more money paying a TIG welder than to just order up a new pan.
After searching around, we found the Holley GM LS Retrofit oil pan. This pan is nice for several reasons. First and foremost, it’s roughly three inches shorter in height than the truck oil pan. Second, it still allows us to mount the oil filter in the stock location. We’ve seen others that required the use of a remote mounted oil filter, which is an added cost for us. Lastly, the oil pan kit comes complete with everything needed, including the correct pickup tube. Swapping out the pan took about an hour.
Since all LS engines are fuel injected, a high-pressure fuel pump will be required, unless you’re planning on installing a carbureted set up. Luckily, there are a lot of different options out there. Some companies make gas tanks with high pressure fuel pumps inside, much like a factory set up. Another option is to use an external mounted pump, but you will have to install some sort of sump to suck up fuel.
We went shopping at a buddy’s house and found an extra fuel pump, pre-filter, and a post-filter laying around. We picked these up and headed back home. But with the external pump setup, we needed a sump to make sure we don’t ever starve the pump of fuel. Moroso has this slick weld-on fuel sump that has two 3/8-inch NPT bungs already installed.
Normally, when you install such a sump, you’d install it near the rear of the car. This allows the fuel that sloshes back in the tank to reach the sump. Since this car is a cruiser and because of how the tank sits in the car, we opted to mount it in front of the tank. We slapped it on our tank and called it a day. This allowed us to get adequate fuel to the engine, as well as plumb the return to the lowest point.
Now, we aren’t ones to skimp on a fuel system. If they fail, your car burns to the ground. With that in mind, we decided to splurge and use AN fittings and quality hose.
We called Holley, and ordered Earl’s Hose and Fittings. The extra cost was easy insurance for us, and has already paid dividends. The first time we turned the key and primed the system, we had zero leaks.
The last piece of the fuel system that required attention was the throttle linkage. Some LS engines utilize a cable, while others are drive by wire. On this set up, our LQ4 had the throttle by cable set up, which was included from Just Chevy Trucks. The throttle cable that came with it was about two feet too short for us to be able to use. Once again we called up Lokar Performance Products, who sent us out a 48-inch throttle cable. After fabricating a small bracket on the floor to attach the cable to the factory throttle pedal, we were in business. Their universal throttle cable really made it easy to adapt to any car, and it only took us about an hour to install.
The last thing to consider are the engine accessories themselves. Not all LS engine accessory mounting is the same; a Corvette differs from a Silverado. You might have to move some accessories to clear cross members, gear boxes, suspension, or other items. There are options for complete aftermarket drive systems that compact everything, but drive the price up of a conversion.
With a lot of measuring and a little massaging, we were able to get the factory truck accessories to work. The only accessory we couldn’t get to work was the A/C compressor. We do plan to add A/C at a later date, which is easy to do. There are several companies that make aftermarket brackets that mount the A/C compressor high off the passenger side head. The factory A/C compressors are mounted low on the passenger side right where the cross member sits. We removed the compressor and the rest of the accessories fit fine.
The cherry on top of this swap was bolting on the cold air intake. You should never just stick a filter on the end of the throttle body. In a pinch it will work, but it’s not how these motors are designed to operate and you’ll lose a lot of performance. The best way is to install a cold air intake system. We tried to install the factory intake tubes, but on this car, there was simply no way to make it work. The only way it would have worked was to cut a hole in the inner fender, and mount the air filter by the tire. This would cause a lot of debris to get stuck in the filter, along with water and possible damage from rocks.
What we did was contact our friends at Spectre Performance. They already make intake kits for popular LS swaps, such as Camaro and Chevelle. However this car is an oddball so we needed something custom. We showed them what we had and they sent us a box full of universal products to fit and choose from. In the end a simple 90-degree bend with a few couplers and one of their 9-inch long filters did the job perfectly.
Finishing the Beast
Swapping an LS engine isn’t something to be afraid of. We have a lot of time invested in this swap, but what’s great is that we did it in a normal garage, on a budget. We spent a lot of ours scratching our heads, checking out what we had in storage, and fabricating little pieces to make everything work. But in the end we completed the entire swap for $6,165. There could of been cheaper ways to do some things, but we also looked at it from a time standpoint as well. Remember that some of the items needed might not be needed for your swap.
- LQ4 Engine: $1,300, Just Chevy Trucks
- Wiring Harness: $500, Just Chevy Trucks
- Rebuilt 4L80E Transmission: $1,250, Just Chevy Trucks
- Shipping from Maine to California: $450
- Oil Pan: $372, Holley
- Transmission Mount: $15, Rock Auto
- Shifter Linkage: $75, Lokar
- Throttle Cable: $60, Lokar
- Driveshaft: $1,050, Inland Empire Driveline
- Fuel and Trans System Plumbing: $300, Holley/Earl’s Hose and Fittings
- Fuel Sump Pan: $73, Moroso
- Radiator and Fans: $60, Craigslist
- New Radiator: $100, O’Reilly Auto
- Radiator Hoses: $70, Rock Auto
- Steering Coupler: $70, Borgesen
- Power Steering Hose: $75, The Hose Man
- Fluids: $100, Auto Zone
- Cold Air Intake System: $145, Spectre Performance
- Exhaust: $100, Local shop
- GRAND TOTAL = $6,165
For just slightly over $6,000, we were able to swap in a modern engine and transmission package from a salvage yard. We can say that it’s worth every penny too. There’s no timing to tweak, carburetor that needs adjusting, or worrying about overheating. You hop in and go – just like a modern car. The car now does 75 mph on the freeway, or can sit in traffic all day and not overheat. Is $6,000 still too much for your budget? Not a problem. You can definitely complete the swap cheaper.
For example, you don’t have to install a new transmission. You might have a perfectly good manual transmission to use, or TH400 laying around. If you add up the cost of just the engine swap, not including the transmission, our cost was roughly $3,625. If you’re handy and can do your own wiring, you can save $500. Or you might have some parts laying around that you could use to make the swap cheaper, like a radiator or fuel tank. You might even have the tools on hand to bend and weld your own exhaust, saving another $100.
Every swap is going to be unique and have different challenges and costs associated with it. We wanted to show you that it’s still not as expensive as you think. The swap is slightly more than rebuilding a basic small-block, depending on how much work is needed. But for a few dollars more you get a huge jump in technology, so why not?