Chevrolet Performance 19540157 LS376/525 LS3 Crate Engine, 525 HP

GM's current part number for this Chevrolet Performance long block is 19540157, replacing the earlier 19435104 designation on what is still, mechanically, the same LS376/525 combination: 525 horsepower, with peak torque of 486 lb-ft arriving at 5,200 rpm and horsepower peaking near 6,200 rpm.

Not your average LS376/525 listing

Two things set this listing apart from a generic LS376/525 build: Chevrolet Performance marks it for competition use only and states it is not intended for marine applications, and GM specifies it ships without exhaust manifolds, a flexplate, a flywheel, or any electronics. Running it requires the separately sold LS376/525 engine controller kit, and GM points builders working on older vehicles toward its Muscle Car Oil Pan Kit.

Bottom end and heads

Six-bolt, cross-bolted main caps secure a cast aluminum block, and the rotating assembly pairs a nodular-iron crank with powdered-metal rods; hypereutectic aluminum pistons complete the package. The hydraulic roller camshaft is tuned toward high-rpm breathing, with intake duration of 226 degrees against 236 degrees on the exhaust side. Bore and stroke measure 4.065 inches by 3.622 inches, compression is 10.7:1, and 68cc chambers feed the L92-style aluminum heads, with intake valves sized at 2.165 inches and exhaust valves at 1.590 inches. A 58x reluctor wheel is fitted, with maximum recommended engine speed at 6,600 rpm.

Before you order

Because the controller kit and oil pan kit are sold separately, budget for those pieces and plan the rest of your installation before committing. Premium pump fuel is recommended given the 10.7:1 compression ratio, and this engine is built for competition rather than marine use.