![BPP12110356 GM Gen II/IV LS Bare Block, 4 in. Bore, 9.240 in. Deck, Cast Mains [4 Bolts/Studs per Cylinder]](https://www.jegs.com/images/mini_750/100/138/138-bpp12110356.jpg)
BPP12110356 GM Gen II/IV LS Bare Block, 4 in. Bore, 9.240 in. Deck, Cast Mains [4 Bolts/Studs per Cylinder]
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.