The bargain here is GMPP's...
The bargain here is GMPP's 376ci (6.2L) LSX partial long-block. It comes without the top end induction. Add your own EFI or carb setup, or add GMPP's intake. With the LS3's top end, power is around 450 hp.
Power Brokers:LSX Crate Motors
GM Performance Parts has just released the first pair of crate engines based on the LSX Bowtie block: the LSX376 and LSX454. The LSX Bowtie block is the foundation of GMPP's LSX line, and is designed to support high-horsepower LS engine combinations (read: 2,000 hp) that are suitable for the street, or racing applications. The new crate engines leverage the expertise of GM's LS engine program, but take it to the next level with race-caliber components. They join GMPP's production-based LS crate engines and engine controllers to comprise the industry's most complete lineup of LS engines, components, and systems.
LSX376
The LSX376 (PN 19171049) is an affordable performer that combines the economical and strong LSX block with the production LS3 engine's high-flow, L92-style cylinder heads and camshaft. Unique, forged-aluminum LSX pistons are also part of the assembly. Unique LSX376-logo valve covers distinguish the new crate engine. When fitted with a production LS3 intake manifold and injection system (not included), the LSX376 is capable of producing 450 horsepower and 430 lb-ft of torque. It can also be fitted with a carbureted induction system that can be tuned for greater power. The manifold and carburetor are available from GMPP.
LSX454
The new LSX454 crate engine (part number 19166972) uses the LSX block, along with an all-forged rotating assembly, and a pair of GMPP's new deep-breathing LSX six-bolt cylinder heads. It's topped with a high-rise intake manifold and four-barrel carburetor, so it's a more complete turnkey assembly than the LSX376. The new LSX six-bolt cylinder heads are based on the race-derived LS7 heads from the Corvette Z06. They enable tremendous low-end torque and high-rpm power. The LSX454 is rated at 620 horsepower and 600 lb-ft of torque. The LSX454 is delivered in deluxe form, so it includes everything from the carburetor to the water pump. It also comes dressed with new orange powdercoated valve covers with "LSX454" logos engraved, and painted black.
By The Numbers
| LSX376 |
| Part number: | 19171049 |
| Engine type: | LSX Series Gen IV small-block V-8 |
| Displacement: | 376ci/6.2L |
| Bore x stroke: | 4.06 x 3.62 |
| Block (P/N 19166454): | LSX cast iron with six-bolt, cross-bolted main caps |
| Crankshaft: | nodular iron |
| Connecting rods: | powdered metal |
| Pistons: | forged aluminum |
| Camshaft type: | hydraulic roller |
| Valve lift: | 0.551 intake/0.522 exhaust |
| Duration (deg @ 0.050 in): | 204 intake/211 exhaust |
| Cylinder heads (P/N 12598594): | LS3 rectangular port; as-cast with 68cc chambers |
| Valve size: | 2.16 intake/1.59 exhaust |
| Compression ratio: | 10.7:1 |
| Rocker arms: | investment cast, roller trunnion |
| Rocker arm ratio: | 1.7:1 |
| Recommended fuel: | 92 octane |
| Reluctor wheel: | 58X |
| Balanced: | internal |
| LSX454 |
| Part number: | 19166972 |
| Engine type: | LSX Series Gen IV small-block V-8 |
| Displacement: | 454 ci/7.4 L |
| Bore x stroke: | 4.185 x 4.125 inch |
| Block (P/N 19166454): | LSX cast iron with 6-bolt, cross-bolted main caps |
| Crankshaft: | 4340 forged steel |
| Connecting rods: | 4340 forged steel |
| Pistons: | forged aluminum |
| Camshaft type: | hydraulic roller |
| Valve lift: | 0.635-inch intake/0.635-inch exhaust duration (deg @ 0.050 in): 236 intake/240 exhaust |
| Cylinder heads (P/N 12598594): | LSX454 rectangular port; with 70cc chambers |
| Valve size: | 2.20 intake/1.61 exhaust |
| Compression ratio: | 11:1 |
| Rocker arms: | investment cast, roller trunnion |
| Rocker arm ratio: | 1.8:1 |
| Recommended fuel: | 92 octane |
| Reluctor wheel: | 58X |
| Balanced: | internal |

New six-bolt LSX cylinder...

New six-bolt LSX cylinder heads employ NASCAR flow technology to boost flow capacity high enough to support over 600 hp in box-stock form-well into aftermarket big-block territory.

The new GM Performance Parts...

The new GM Performance Parts 454 LSX crate motor puts out 620 hp on pump gas. That's as much as GMPP's hydraulic roller 572ci big-block crate motor.