![BPP12110330 Big Block Chevy Bare Block, 4.600 in. Bore, 9.800 in. Deck, Billet Mains [2-Piece Rear Main]](https://www.jegs.com/images/mini_750/100/138/138-bpp12110330.jpg)
BPP12110330 Big Block Chevy Bare Block, 4.600 in. Bore, 9.800 in. Deck, Billet Mains [2-Piece Rear Main]
This GM Big Block Compatible bare block is cast from EN-GJL-250 Iron with a 9.800" +.005" / -.000" deck height and a 4.595" to 4.597" rough bore. It accepts up to a 4.630" bore and 4.750" stroke for as much as 598 cubic inches. The mains use billet steel caps with 1/2"-13 fasteners and a 2 piece seal (oem gen iv).
BluePrint Engines BPP12110330 Engine Block Features:
- Deck height: 9.800" +.005" / -.000"
- Rough bore: 4.595" to 4.597"
- Maximum bore: 4.630"
- Maximum stroke: 4.750"
- Cylinder wall thickness: .310" Nominal @ Max Bore
- Main caps: Billet Steel
- Oil system: Priority Main
- Weight with main caps: 240-260lbs
BluePrint Engines BPP12110330 Installation Notes:
- Rear main seal: 2 piece Seal (OEM GEN IV)
- Timing cover: OEM GEN IV
- Oil pan: OEM (GEN IV)
- Oil pump: OEM
- Starter: OEM
- Cam bearings: Durabond GM-12
- Head bolt/stud threads: 7/16-14 UNC
- Freeze/core plugs: 1-5/8" x 8
Build It From the Foundation Up
BluePrint Engines bare engine blocks give builders a premium starting point for high-performance street, strip, and marine combinations. Designed as serious foundations for popular GM, Ford, and LS-based platforms, these cast-iron blocks are engineered for strength, dimensional stability, and accurate machining so your rotating assembly, valvetrain, and sealing surfaces come together with confidence. With BluePrint’s modern manufacturing and in-house machining capabilities supporting consistent bore geometry and critical tolerances, you get a block that’s ready for a custom build path, from fresh stock-style replacements to large-displacement stroker projects.