LS Engine Swap Tips - Heart Transplant

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From the July, 2011 issue of Super Chevy / By Mike Copeland / Photography by The Super Chevy Archives
Back in 2009 when LS swaps were gaining ground, we had Mike Copeland write an in-depth story on the things you need to consider when swapping in an LS engine into a vintage muscle car. Mike was the project manager for the Performance Vehicles division at GM then and is now the operations manager at Lingenfelter Performance Engineering, so he knows a few things about the LS platform. Fast forward just two years and the aftermarket is in high gear, producing a lot more products to support such a task.

It was time for us to bring that story up to date and also show y'all where to get the latest and greatest products for the LS. We have broken the story up into specific sections like wiring and exhaust that will highlight the things you need to consider and the products that are available.

Engine


First off, you need to know where you can actually get the LS motor for your swap. Obviously a wrecking yard will be a good place to look for used engines. Try and pick up the computer, harness and gas pedal if at all possible. If you go that route, make sure the yard offers some sort of return/exchange policy just in case your engine turns out to be broken. If you would rather have something new, then you will need to contact an aftermarket company. GM Performance Parts has crate versions of just about every LS available from the simple LS1 up to the badass supercharged LS9. Not to be outdone by GMPP there are places like Mast Motorsports and Pace Performance that will sell you a complete LS engine ready to go. If you want to build one from scratch, look to Dart, RHS and GMPP for short- and tall-deck blocks. These allow you to build LS-based engines all the way to past 500 ci.

GM Performance Parts, like we mentioned earlier, has the entire LS family covered and is really proud of its eco-friendly E-Rod program. In a nutshell, the E-Rod package is a crate engine combined with engine wiring harness, engine control module, exhaust manifolds, catalytic converters, oxygen sensors and sensor bosses, fuel tank evaporative emissions canister, mass airflow sensor and sensor boss, accelerator pedal (for use with the electronic throttle), air filter and instruction manual. The highest horsepower E-Rod package right now is the LSA. It's the engine out of the Cadillac CTS-V series of high-performance vehicles. Using an advanced, highly efficient four-lobe supercharger, the LSA 6.2L engine is rated at 556 horsepower.

Pace Performance designed this little Screamin' Mimi engine package using GM's 4.8L truck engines. The dyno-tested package made 300 horsepower and 340 lb-ft. This engine only requires a two-wire hook-up to run, timing is preset (but can be adjusted), does not require oxygen sensors and runs on low 5-7 psi fuel pressures. It comes with a 12-month limited parts replacement warranty and is offered for $2999.95.

For the LS guy who wants something really gnarly, check out Dart's LS1-style billet aluminum block. Machined on precision CNC equipment from a solid billet of 6061 aluminum, the Dart LS1 block offers virtually unlimited choices in deck height, cylinder bore centerline, bore diameter and lifter/cam configurations. The Dart LS1-style billet block is available with or without water jackets and can be ordered with additional head bolts, custom motor mount bosses and optional camshaft diameters.

Flex Plates & Flywheels


The rear snout on the crankshaft on all LS-series engines is 0.400 thousands short compared to traditional small- or big-block Chevy engines. If you are using an LS engine/transmission package, there is no issue. If you are installing a traditional GM transmission on LS engines, changes must be made to locate the flywheel or flex plate in the correct location.

Engineered to prevent cracking and ring gear breakage commonly found in lesser quality flexplates, this new design includes an integrated early-style GM torque converter pattern that gives the option of using an LS-series or earlier model transmission with LS engines, including the LS9 or LSA. In addition, the precision-ground, 3/16-inch-thick, A36 steel plate material is 0.067 inch thicker than the original factory piece, which makes it stronger. Finally, the most important feature is that these performance flexplates have been tested and are SFI 29.1--approved for strength and durability.

The APS starters from MSD feature a 3.4-horsepower motor powering a 4.4:1 reduction gearset to deliver great torque--enough for 18:1 compression racing engines. Inside the compact housing, MSD put two ball bearings to guide the balanced armature through countless smooth engagements and starts. Another handy feature is that the billet-mounting block can be rotated in different positions to help clear oil pans and suspension parts.

Intake Manifolds


There are a number of production-based intake manifolds, as well as a multitude of aftermarket units. The LS1, LS6 and truck manifolds interchange, but the truck manifold is pretty tall so it might pose a hood clearance issue. These engines share a common intake gasket design. The LS6 intake is a popular upgrade for LS1 engines and adds 10 to 15 horsepower. If you are looking to keep the system a bit simpler by running a carburetor, you are in luck as there are a few intakes offered that allow the use of a carb.

The newest thing in the LS intake market is Holley's GM LS3/L92 Modular Hi--Ram-style intake manifold. Coupling this Hi-Ram intake with the high-flowing LS3/L92 cylinder heads has outstanding potential for N/A and forced- induction applications at a budget-minded cost. The base is designed to be modular in configuration to accept a wide range of carbureted and EFI tops and to be attractive to builders and fabricators as the foundation for custom induction systems. EFI fuel rails feature --8 fittings with passages large enough to accommodate high fuel flows and dampen pressure pulsations in the fuel system and come standard with EFI Hi--Ram-style kits.

Reluctor Wheel Identification


Currently, there are two generations of reluctor wheel in the LS family. What's a reluctor wheel? A reluctor wheel is part of the ignition system. Much like a crank trigger, it (combined with a sensor) tells the ECU what position the crank is in, so it can fire the coils off at the correct time. The easiest way to determine which version is which is the location of the cam sensor. Gen-III engines have the cam sensor located in the block at the rear of the intake manifold. Gen-IV engines have the cam sensor located in the front cover. Also, Gen-III engines have 24X crank sensors, and Gen-IV has 58X. The 24X sensor has a black connector, and the 58X has a gray connector. Engine controllers must be matched to this sensor, or the engine will not run.

Complete Swap Kits


Among the newest offerings out there are the complete swap kits. These will include a lot of stuff needed to transplant an LS under the hood in one part number. What is nice about the kits is all the components were developed together so you know the motor mounts and exhaust or throttle body and pedal will work together in you car. The manufacturer will dictate the completeness of the kit; you must decide what you actually need compared to what is packaged together.

FAST's new EZ-EFI kits allow anyone to easily run a GM LS Gen-III/IV engine and transmission outside of its original vehicle and factory controller. The FAST kits are the perfect "no headache" and "no expert required" complete solution for transplanting late-model engines. Everything is covered, from fuel to spark and from engine through electronic transmission. The optional package stages allow you to select the right level of kit based on your individual needs. The kits are available in four different options: Engine Kits with EZ-TCU Transmission Controller; Engine & Manifold Kits; and Engine & Manifold Kits with EZ-TCU Transmission Controller.

Hedman Husler's line of Muscle Rods products consists of headers, engine mounts and transmission crossmember combinations that are vehicle- and transmission-specific. Muscle Rods mounts and crossmembers are designed to ensure that the engine is set in the correct position to allow for factory accessories on the front of the engine, and that the factory recommended 3-to-5 degrees pinion angle is maintained. The company also gives you a choice in exhaust with short- and long-tube headers. The Muscle Rods headers and LS-conversion mount kits are sold separately and are available for Tri-Five and X-frame cars, as well as, A-, B-, F-, G- and X-body vehicles.

Wiring/ Computers


There are multiple sources for wiring harnesses and engine controllers. You can use modified factory components or purchase one of the many kits designed for your specific engine. For the best all around performance and ease of installation, purchasing a complete kit is a good choice. These kits come with all the components required to make your LS engine run and can be hooked up with as few as two wires.

Dominator EFI Vehicle Management Systems are intended for all engine applications, from street to unlimited high-end racing applications. Dominator systems have nearly unlimited capabilities to control any power adder, input or output you can throw at them. How about control a 4L60E transmission as well as the fuel and spark? No problem. There are also enough inputs and outputs to allow the Dominator VMS units to serve as their own data acquisition and control modules. The Dominator VMS will eliminate the need for additional controllers as they are all contained in this one unit.

GM Performance Parts has a controller kit complete with computer and all the components to fire up their crate engines. In the kit you’ll find the accelerator pedal and fuse panel, and each kit comes with all the sensors, cables and connectors you need--and it’s pre-wired and pre-labeled.
The 120-pin hardware is the newest addition to Mast’s lineup of ECMs for Gen-IV LS engines. The M-120 ECM features bank-to-bank active wideband feedback control. This allows for easier application tuning. All of Mast’s M-90 ECM's advanced functions are retained including wide-band knock, VVT control, full sequential fuel injection and drive-by-wire throttle control. The ECM also adds active boost solenoid control for GM LSA and LS9 engine applications. The M-120 ECM is available with pre-programmed calibrations in both Calibrated and Performance packages.

Pedal


If you go with a drive-by-wire throttle body, then you will need the proper pedal to drive it. You can snag these from the salvage yard or companies like Lokar or GMPP. If you go with a cable system, you'll need the correct throttle cable to attach to the throttle body, which Lokar makes as well.
Lokar has partnered with Williams Controls, the world leader in heavy-duty electronic throttle pedals. The unit is a programmable non-contact (solid state) hall effect sensor for most GM applications. The pedal features a splined pedal arm for versatile mounting, and the sensor is programmed on pedal to optimize electrical output for quick throttle response. The company’s billet aluminum LS1 throttle-cable bracket mounts to the stock location on the vehicle. It is designed to keep the throttle cable down low and close to the manifold. The bracket is available with a single hole or a double hole for a cruise-control cable.

Mounts


All LS-series engines have the exact same mounting bosses for the engine mounts. There are many aftermarket companies—Trans Dapt, Holley and Chris Alston’s Chassisworks—making adapter mounts to install an LS into almost any vehicle made. Having the engine sit in the correct position will make installing other components like headers or oil pans much easier. Also note that some iron LS blocks have undrilled bosses and need to be drilled to mount some accessories.

Chassisworks billet-aluminum motor mounts and steel frame adapters enable direct bolt-in installation of Chevrolet LS engines in '67-69 Camaros and '68-74 Novas with stock subframes. The mounts feature durable polyurethane bushings and maintain correct engine position and drivetrain angle.

Transmission


All Gen III/IV engines share a common transmission bolt pattern. It is the same as the traditional Chevy pattern, with one missing bolt. The center hole on the passenger side is not drilled or tapped in production blocks because the hole would protrude into the water jacket. Obviously, a new 4L-series transmission will bolt right up without any issues, but you will need a controller for it.
For computer-controlled transmissions, check out the new TCI EZ-TCU by FAST. No software, laptop or tuning experience is required. Simply install this new transmission control unit according to the enclosed instructions, and then start the system by answering the simple Setup Wizard questions on the included handheld unit. It is fully configured and ready to run right out of the box, but for those who demand customization the unit is also optionally fully programmable based on load, speed and rpm.

Performance Automatic offers a 4L60E GM Electronic Overdrive Transmission Street Smart Package for all LS-powered vehicles. This package includes a Stage 1 4L60E transmission that features many gear-train and hydraulic modifications, a custom-built 2,500 lock-up stall converter, a new rubber mount, the company's Smart Shift Trans controller (no laptop required), dipstick, filler tube and a one-year warranty.

Quick Time offers an SFI-certified bellhousing to bolt just about any trans behind your LS engine, including Tremecs, Richmonds and all the popular GM units. These will bolt right to the back of the LS and then allow for the manual trans of your choice all in an SFI-approved package.

Accessory Drive Systems


Almost every vehicle GM builds with an LS engine has a different accessory drive. Because of availability, the most popular systems used in engine swaps are the Corvette and the F-car. Another popular system is from the CTS-V. It tucks in closer to the engine and works well in limited-space applications. If you like smooth and shiny, then you can look to companies like March or Billet Specialties. Remember, the crank pulley must match the accessory drive system you are using
The Eddie Motorsports drive system brackets and pulleys are CNC-machined from high-quality billet aluminum. The systems utilize stainless steel hardware for longevity. All of the systems are available in machined finish, polished, anodized or powdercoated in various colors. Complete systems include the following billet parts: crank pulley, water pump pulley, P/S pump pulley, alternator pulley, A/C compressor cover, tensioner cover, A/C compressor manifold and all necessary brackets.

Billet Specialties' top-mount kit really makes it easy to cover the front-end accessory drive part. The LS motors bought used come from many platforms and have three different versions of a crank pulley/balancer and just as many water pumps. Tru Trac solves this problem because you get the water pump (from Edelbrock) and the crank damper (from ATI) along with the other components to ensure it all lines up and the customer does not have to spend time identifying what damper and water pump he has and what will or will not work with it. The Tru Trac includes everything you need to walk away with a complete front engine accessory drive system that only has to be plumbed for power steering and A/C.

This single-belt serpentine system is a complete front engine solution. The compact design eliminates interference with A/C compressor and crossmember. These kits will fit LS-series and other GM Gen-III and Gen-IV engines, including the LQ9 and L92 GM crate engines, and they will work with LS1- and LS2-style throttle bodies. These easy-to-install systems are supplied with everything you need on the front of the engine, including new water pump, SFI-approved harmonic damper, belt and chrome hardware. Kits with power steering include lightweight aluminum pump with billet aluminum mini reservoir.

Oil Pans


There are numerous versions of oil pans available, from both GM and the aftermarket. On the factory side, look to the F-body, GTO, or Hummer H3 pan, as those will usually fit the best. You may see some interference with the steering linkage, and the sump will most likely hang below the crossmember. If you want the pan to really tuck up into the chassis, then you will need to look at the aftermarket stuff. No matter what pan you go with, make sure to match the oil pick-up and dipstick to the pan. When you install the oil pick-up, make sure the tube and O-ring seal are straight in the oil pump. If not, you can have low oil pressure and damage your new engine.

The factory LS pans don't always fit or they hang too low in some swap situations, so Holley's new LS Retro-fit engine oil pans are designed to help. It provides maximum clearance to the chassis and ground, plus provides an OEM fitment for durability and proper sealing. It provides OEM-type fitment, oil filter mounting, oil cooler port provision, engine NVH suppression, flange gasket and sealing, proper structural rigidity and bellhousing attachments.

Like the OEM LS oil pan, Mast's LS conversion oil pan is manufactured from rugged cast aluminum, and a thick pan rail maintains the oil pan as a stressed member. The short front pan depth and optimum sump depth balances oil capacity while fitting virtually any chassis. Features include the production GM pressure relief valve bypass built into pan, cored and baffled for excellent oil control, oiling circuitry with -10AN fittings eliminates need for adapters, driver-side oil drain, rear -6AN port for optional oil pressure gauge tap, oil pickup to fit almost any stroke, enlarged oil passage holes for reduced oil pressure losses and internal cross-drilling to eliminate the external oil loop cap when using standard oil filters.

Cooling Systems


All LS water pumps share a common bolt pattern and will interchange between engines. This allows you to use an LS3 water pump in space-confined applications. It works with most accessory drive systems and is much shorter (over 1 inch) on the front compared to an LS1 pump. Both radiator hoses come out on the right side of the engine. All production LS engines are built with a 195-degree thermostat. Never remove the thermostat from an LS-based engine since it's designed to direct flow through the engine. Removing it can cause engine damage.

The cooling system design on an LS engine seems to work best with a radiator that has both the inlet and outlet on the passenger side. AutoRad makes radiators with this configuration in a cross-flow unit just for LS-swap applications. Not only do you get a killer radiator, it is stuffed into an aluminum core support like the '68-72 Nova piece shown here.

Steam Tubes


All LS-based engines have a small hose connected to the front of the cylinder heads. In some applications, it is hooked to the lower left side of the throttle body, then to the radiator. It vents air from the top of the cylinder heads, and not hooking it up can cause engine damage. The LS6-style runs left to right and has two plugs for the rear holes. It will be good for carb manifolds and blower applications. If you are running the stock intake, then pick up the corresponding steam tubes.

Fuel Systems


The LS engines came with both "return" and "returnless" fuel rails. Early ('97, '98 and some '99) LS engines were equipped with return-style systems. Later LS engines ('99-up) have a returnless-style fuel system. The fuel-injection system for the LS wants to see 56 psi of constant fuel pressure. If you are going the injected route, you will need to run a return line or reconfigure your fuel lines to accept the returnless pump. If you are going the carb route, the fuel system you had in place should be sufficient as long as you are running an electric fuel pump, as the LS block has no provisions for a mechanical pump.

The Aeromotive 340 Stealth fuel pump is a high-output, in-tank, electric fuel pump that'll feed your LS. The Aeromotive 340 is a compact, lightweight pump that bolts into many existing hanger assemblies if you already have an EFI tank. Not completely nailed down at the time of this story, but the guys at Aeromotive are teaming up with a tank manufacturer to make ready-to-go EFI tanks for the most popular old muscle cars.

Exhaust


For the most part, you have two options when it comes to bolt-on exhaust: use the stock manifolds, or get a set of headers. GM offers a lot of different manifolds, but for most of the Bow Tie family of cars the GTO or Trailblazer SS manifolds are a good swap option. On the aftermarket side, you have a lot of options from short-tube to full-length headers. A few things to keep in mind when picking an aftermarket header: Are they made for your specific vehicle, and what motor mounts were used? Since the motor mounts dictate the position of the block, they directly affect the header fitment and clearance.

These street rod/universal Super Competition headers work great for those tight-fit installations where framerails are close to the engine block. Stock motor mounts can be used. Because the collector exits parallel with the oil pan rail, maximum ground clearance is allowed. These headers come complete with gaskets, header bolts and collector reducers. They're available in chrome, high heat-resistant black paint or Hooker's metallic ceramic thermal barrier coating.
Doug's Headers offers a full-length design for the '67-69 Camaro and '68-74 Nova with an LS1/LS6 engine swap. These headers are built with 3/8-inch-thick machined flanges at the cylinder head.

The four-tube under-chassis exit design is made from 16-gauge tubing for durability with 1-3/4-inch primaries and 3-inch collectors. For proper engine location and guaranteed header fit, use the Doug's motor-mount adaptor plate kit. The headers come standard with a polished metallic ceramic coating, 1,100-degree-rated gaskets and all necessary installation hardware, including collector reducers with welded O2 sensor bungs and O2 sensor extension harnesses



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