ratings while making significant horsepower numbers. In the past it was not possible for a small-block Chevy to make 400 hp and get 20 mpg. With an LS engine, it is not only achievable, it’s standard.
The 2013 Z06 Corvette has an LS7 that cranks out 505 hp and maintains 24 mpg highway and 15 mpg city for a combined 18-mpg average. A Gen I small-block Chevy cannot get close to those numbers. A stock Vortec 5.3-liter with an overdrive automatic can produce 350 hp and 20 mpg with a custom ECM tune.
These factors combined make the Gen III/IV engines the most popular swap since the original small-block Chevy hit dealers in 1955. With so many variations, there is sure to be a Gen III/IV engine to suit your application.
One of the most popular swaps is the 1964–1972 GM A-Body platform. This generation of vehicles covers every GM make (except Cadillac) and features the most popular muscle car models. These include the Buick Special, Skylark, Sportwagon, and GS. Chevrolet cars are the Chevelle, Concours Estate Wagon, Nomad, Malibu, and El Camino. Oldsmobile models include the F85, Cutlass, Cutlass Supreme, Vista Cruiser, and Cutlass 442. Fiercely independent Pontiac A-Body cars are the Tempest, Safari, LeMans, and GTO. The differences among models means different requirements for installing an LS or LT engine, most notably the frame stands for the motor mounts.
Performance Project: The “Take-Out” Procedure for a Vortec 5.3-Liter Salvage Yard Engine
Although some swappers purchase crate engines or salvage yard take-out engines, you can save a lot of money by finding a wrecked vehicle and yanking the engine yourself. GMC and Chevy trucks are the most abundant source for LS-series engines, but it’s important to find one with less than 200,000 miles on the odometer. When properly maintained, an LS engine can make 300,000 miles before needing a rebuild. An LS engine with 150,000 or fewer miles usually has a lot of life left and does not require a rebuild.
For this project, I bought a still-drivable 2003 Chevy 1500 truck with rear-end damage. The engine and transmission ran well and it could have been repaired. However, it had a salvage title and was a bargain at $500, so I went ahead with the swap. I rolled the truck into the shop and began stripping it down by removing the fenders. Although removing the fenders isn’t required, it makes accessing all the bolts much easier and the truck is slated for the scrap yard anyway. Within 10 minutes the fenders were off.
Next, I removed the core support. You can leave the radiator in the car until you are ready to pull it. Two body bushings on the frame connect the core support with through-bolts; remove them. The fenders are attached to the core support with a couple of bolts as well. This opens the front of the engine, making removal from the chassis easier.
A lot of hoses and wires attach to the engine. The coolant needs to be drained; you can do this last if you prefer as it usually makes a mess. The A/C components (compressor, hoses, and condenser) can remain in the truck. You can’t use the stock A/C compressor in swaps, so there is no point in purging the gas from the system. Carefully remove each wire connector from the engine, cut any zipties or straps holding the harness to the engine or chassis (don’t cut any wires!), and remove the harness. The hoses can be removed or simply cut because you need new hoses for your swap install. The ECM is located on the driver’s side of the vehicle.
At this point, the engine should be unfettered. If you are removing the engine and transmission as one unit, unbolt the transmission from its mount, support it with a jack, and remove the transmission crossmember. Disconnect the transmission wiring harness, shifter, driveshaft, and cooling lines. Unbolt the engine from the motor mounts on the frame and attach an engine hoist. Lift the engine (with the transmission attached) and slide it out of the chassis.
If you are taking just the engine, you need to support the front of the transmission from the ground first. Then use a flywheel turner to spin the flexplate until you reach each torque converter bolt and remove them all. At this point, you can unbolt the bellhousing and remove the engine separate from the transmission.
Because this is a drive-by-wire (DBW) vehicle, I removed the pedal and throttle actuator control (TAC) module and installed them in the swap project car. The TAC module is located on the firewall next to the power brake booster. Don’t forget these two items; you will need them if you plan to use the stock computer. If not, take them anyway, someone will want them.
With a little degreaser and elbow grease, your new LS engine will be ready for prime time in just a few minutes. Don’t forget to save the secondary sensors such as the mass airflow (MAF) sensor from the air inlet tube.
