RodderMods

Comparison

LS swap: a new crate from Summit vs a used pullout from eBay

The 5.3 is cheap new or used; the LS3 is where a used pullout saves $10,000. Prices, part numbers and the catches, checked October 2026.

By Roddermods Admin,

GM's LS engines are the default swap for classic Chevys, and for plenty of Fords and Mopars too. They're light, they make good power, and every chassis builder has mounts for them. Here's what an LS costs new from Summit Racing compared with a used pullout from eBay Motors, for the two versions most people buy: the truck 5.3 and the 6.2 LS3.

The 5.3: cheap either way

New

Summit Racing's Chevy LS 5.3L 450 HP long block (SUM-150153) is $3,949.99. It's a remanufactured long block with a 24x crank reluctor. Summit notes that it needs an ECU tune and recommends injectors of about 36 lb/hr. It does not include the intake, throttle body, computer, harness, oil pan, valve covers, timing cover, water pump, balancer, flywheel, plugs or wires, so budget for all of those.

Used

  • 5.3 LM7 and 4L60E from a 2005 Silverado, 49k miles: $6,500 or best offer, with accessories, starter, sensors and computer. The seller says a new harness and programming are still needed. $350 freight, 30-day returns.
  • 5.3 and 4L60E from a 2003 Silverado, 189k miles: sold October 1 for $2,350, with free freight to a dock. The title mentions wiring and a computer, but the description doesn't confirm them.

A used 5.3 with its automatic runs about $2,350 to $6,500, compared with $3,949.99 for the Summit long block alone. For a budget build, a low-mile pullout with its computer is hard to beat.

The LS3: where used saves the most

New

  • Engine and controller: the Chevrolet Performance LS3 430 HP dressed long block (19540155) is $10,755.99, with intake, throttle body, coils, injectors, oil pan, water pump and balancer. The LS3 controller kit (19540147) is $2,320.95, with the engine harness, MAF, oxygen sensors and pedal. The transmission controller is separate.
  • With a 4L80E: a GearStar 4L80E Level 3 is $7,445.00 and its Quick4 controller is $879.99. That's $21,401.93 for engine, controller, transmission and transmission controller.
  • The GM package: Chevrolet Performance's Connect and Cruise LS3 (480 hp) with 6L80E is $20,662.18 and includes the engine, transmission, transmission controller, ECM, harness and installation kit. It's the cheaper factory route.
  • A SuperMatic 6L80E on its own is $6,323.99 with converter, controller and harness.
  • Another option for the engine computer is Holley's Terminator X Max 550-928 ($2,199.95), which also runs a pre-2009 4L60E or 4L80E. Its page says injectors and coils are included, which we doubt, so confirm before you count on it.

Used

A used LS3 and automatic with its computer is about $9,000 to $10,000, against about $20,700 new. Even after a $600 standalone harness, a tune and freight, that's close to $10,000 saved.

LS1 with a T56

The LS1 and T56 from a 1998-2002 Camaro or Firebird is the classic manual swap. A 2002 Camaro LS1 and T56 with 86k miles and a run video was $6,395 with free freight to a business. A 2001 Trans Am pair asked $9,100 before the listing ended. New, a Tremec T56 Magnum is $3,545.00 on its own.

The catches with a used LS

  • Plan on a standalone harness ($589 to $649 from PSI Conversion) and a tune that removes the factory anti-theft.
  • Freight is usually $350 to $500, and only to a business with a forklift or dock.
  • Returns are often not accepted, and mileage is the seller's word.

What you need either way

Mounts, an oil pan that clears your crossmember, headers or swap manifolds, a radiator and fans sized for the engine, an EFI fuel system, a crossmember and a driveshaft. Find makers for your car on our Powertrain & Fuel Delivery, Transmission and Cooling pages, and see how it adds up on a real car in our '61 Corvette drivetrain plan.

Prices checked October 8, 2026. eBay listings come and go, so treat them as examples of what's out there.

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