BluePrint Engines 415 HP 347ci Small Block Short Block Mustang 65-73

Increase power and torque in your classic build with this small block engine. Designed to deliver improved performance over stock displacement engines, this stroker engine setup provides strong mid-range torque and high-RPM capability while maintaining street-friendly reliability.

This short block is built on a high-strength cast iron block, providing durability under demanding conditions. The 3.400" stroke and 4.000" bore combination delivers increased displacement, while the splayed 4-bolt main design and priority main oiling system enhance strength and longevity. With a 10.0:1 compression ratio and 28oz external balance, this engine is well-suited for aggressive naturally aspirated performance builds.

Features and Benefits:
- 347 cubic inch stroker small block increases power and torque
- Forged pistons and connecting rods improve durability
- Cast crankshaft provides reliable performance
- 10.0:1 compression ratio for strong performance output
- Splayed 4-bolt main increases bottom-end strength
- High-strength cast iron block with reinforced webbing
- Priority main oiling improves lubrication
- 1-piece rear main seal helps prevent leaks
- 28oz externally balanced front and rear
- Improved water jacket design

Specifications:
- Displacement: 347ci
- Bore: 4.000"
- Stroke: 3.400"
- Compression ratio: 10.0:1
- Connecting rod length: 5.400"
- Piston type: forged (9cc)
- Balance: internal 28oz external