RHS 54903U LS Aluminum Race Block (Ready to Hone) 9.250" Standard Deck - 4.120" BoreStandard Deck Height (9. 250) Needs Final Finish Hone Before Assembly 5. 87" Cylinder Sleeve Length 4. 120" Bore Engineers at RHS have designed a high performance aluminum engine block for GM LS applications to meet the needs of race and street performance engine builders alike. To go beyond the limitations of other existing LS blocks, the new RHS LS Race Block is available in both standard deck and tall deck height configurations. Additionally, this