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Atk High Performance Gm 350 390 Hp Stage 3 Long Block Crate Engines Hp89C
$3.000
The ATK High Performance GM 350 Stage 3 Long Block (HP89C) delivers 390 horsepower of robust, high-performance power for Chevrolet vehicles, classic muscle cars, and street builds.
Fully assembled and factory-tested, this long block ensures reliable performance, consistent power delivery, and turnkey installation for street, mild performance, or restoration projects.
The GM 350 Stage 3 Long Block (Part #HP89C) is engineered for enthusiasts seeking enhanced performance and durability.
This Stage 3 long block includes precision-engineered components, a forged rotating assembly, Stage 3 camshaft, and upgraded internals, making it ideal for street, mild performance, and restoration builds.
Included Components:
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Engine block
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Cylinder heads
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Camshaft and valve train
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Rotating assembly (crankshaft, rods, pistons)
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Oil pan
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Timing components
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Valve covers
Performance Overview:
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350 C.I.D. (5.7L) Small Block V8 engine
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390 horsepower output
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Stage 3 performance build
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Fully assembled long block for turnkey installation
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Compatible with Chevrolet vehicles, street builds, and muscle cars
Key Features
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ATK High Performance GM 350 Stage 3 long block
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390 horsepower output
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Fully assembled and factory-tested
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Includes all critical engine components for installation
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Engineered for street, mild performance, and restoration builds
Key Technical Specifications
| Specification | Details |
|---|---|
| Brand | ATK High Performance |
| Part Number | HP89C |
| Engine Type | V8, GM 350 Small Block |
| Configuration | Stage 3 Long Block Crate Engine |
| Displacement | 350 C.I.D. / 5.7L |
| Horsepower | 390 Hp |
| Torque | Check Manufacturer Specs |
| Block Material | Cast Iron |
| Cylinder Heads | Aluminum |
| Crankshaft | Forged Steel |
| Connecting Rods | Forged Steel |
| Pistons | Forged Aluminum |
| Camshaft Type | Stage 3 Performance Cam |
| Fuel System | Not Included |
| Fuel Type | Gasoline |
| Ignition System | Not Included |
| Cooling System | Water-Cooled |
| Condition | Brand New / Factory-Tested |
| Country of Origin | United States |
| Included Components | Block, heads, camshaft, rotating assembly, valve train, oil pan, timing components, valve covers |
| Recommended Use | Chevrolet vehicles, street builds, muscle cars, mild performance upgrades, restoration projects |
Compliance & Disclaimer
Horsepower and torque ratings should be verified with ATK High Performance specifications.
Professional installation and proper break-in procedures are recommended.
Not certified for emissions-controlled vehicles in all regions.
Questions & Answers
Have a question about this product? Ask below — we’ll reply as soon as possible.
Return & Refund Policy
- Return Period: Within 30 days of delivery.
- Condition: Unused, original packaging, all accessories included.
- Non-Returnable: Gift cards, personal care, custom or digital items, sale items.
- How to Return: Email support@fastoutboard.com for RMA and return address.
- Shipping: Customer pays unless item is faulty or incorrect.
- Refund: Processed within 5–10 business days after inspection.
Warranty
- Coverage: 1-Year limited warranty for manufacturing defects.
- Excludes: Misuse, wear, or unauthorized repair.
- Claim: Email proof and photos to support@fastoutboard.com.







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