LS Engine Swap Tips - Heart Transplant

Here are the latest products to help you swap an LS motor into your vintage Chevy.

The Super Chevy Archives Jun 16, 2011 0 Comment(s)
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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.

Sucp_1107_swap_25 Heart_transplant Holley_oil_pan 2/31

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.

Sucp_1107_swap_26 Heart_transplant Mast_oil_pan 3/31

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.

Sucp_1107_swap_28 Heart_transplant Autorad_cooling 4/31

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.

Sucp_1107_swap_29 Heart_transplant Pace_tubes 5/31

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.

Sucp_1107_swap_30 Heart_transplant Aeromotive 6/31


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.

Sucp_1107_swap_32 Heart_transplant Hooker_exhaust 7/31

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.


Hooker Headers
Aberdeen, MS 39730
Billet Specialties
La Grange, 60526
TCI Automotive
Ashland, MS 38603
Concept One
Chevrolet Performance Parts
Detroit, MI 48232
Lenexa, KS 66214
Mast Motorsports
Nagodoches, TX 75964
Eddie Motorsports
Rancho Cucamonga, CA 91730
Chris Alston's Chassisworks
Sacramento, CA 95828
QuickTime Inc.
Oskaloosa, IA 52577
Auto Rad
Gainesville, GA 30506
Performance Automatic
Gaithersburg, MD 20879
Holley Performance Products
Bowling Green, KY 42101
Pace Performance




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