Home News Summit Racing Remanufactured 5.3L LS Crate Engine

Summit Racing Remanufactured 5.3L LS Crate Engine

by Scott Mason

Summit Racing’s Remanufactured 5.3L LS Crate Engine: 450 Horsepower with a 2-Year Warranty

It would be pretty big challenge to build a 450 horsepower 5.3L LS long block for what we’re asking for this Summit Racing Remanufactured 5.3L LS Crate Engine. Even if you could, it won’t be backed by a two-year, unlimited mileage warranty like ours is.

The long block is machined and assembled for us by the crate engine experts at ATK, not some guy working in his basement. It’s based on the 5.3L LM7 found in 1999 to 2007 GM pickups and SUVs, but we warmed it up a bit with a Summit Racing Pro LS roller camshaft. It’s just the thing for an LS swap in street-driven muscle cars, hot rods, and light-duty trucks.


  • 450 horsepower, 420 lbs.-ft. of torque, 10:1 compression
  • Seasoned OE LM7/5.3L iron block
  • Oil galley plugs and brass freeze plugs installed and sealed
  • GM 3.622” stroke crankshaft with 24-tooth reluctor wheel, internally balanced
  • GM 6.093” forged powder metal connecting rods
  • New hypereutectic flat top pistons with moly rings
  • Summit Racing Pro LS roller camshaft, .545” lift, 222°/231° duration@.050
  • #799 or #243 GM aluminum cylinder heads, 64cc combustion chambers with 2.00”/1.55” valves
  • GM powdered metal 1.7 ratio rocker arms

NOTES: ECU tuning is required. This engine has an LM7 oil pump tube, which must be replaced with the appropriate tube if using a different OEM or aftermarket oil pan.

Visit the Summit Racing website for more information: https://www.summitracing.com/parts/sum-150153

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