Racing Head Service (RHS) 54903U - LS Block, Std 9.240" Deck, Ready To Hone To 4.120"

- Standard Deck Height (9.240") - Needs Final Finish Hone Before Assembly - 5.87" Cylinder Sleeve Length - 4.120" Bore BLOCK SPECIFICATIONS: - Designed from heavy-duty A357-T6 aluminum material - 4.125”-4.165” siamese cast bore walls w/ press-in spun cast iron liner - Available in standard (9.240”) & tall (9.750”) deck heights w/ beefy .750” deck thickness - Both standard deck (5.67”/5.87”- same as LS7) & tall deck (5.94”/6.38”) cylinder liner lengths available - “Long arm friendly” – Accommodations for up to 4.6” stroke w/ standard rod pin diameters (2.100”) & oversized 60mm camshaft - Raised cam centerline (.388”/9.86mm) to allow larger stroke; 2 extra links in the timing chain – Timing sets available from COMP® - Main cap surface area maximized at mating surface & large fillets from cap to cross bolts for added strength - Designed for clearance – side oil galley moved outboard & engineered rod clearance come standard - Significantly increased windage passage area under bores & around caps over LS7/LSX engines - 6 head bolt design w/ full water jacket around the cylinders (based on LS7 design) - Bay-to-bay breathing improved w/ increased side window area versus LSX & LS7 - Extra large windows in valley for access to inboard “6th” head bolt - Extra long liners for standard (5.87”) & tall (6.38”) decks VALVE TRAIN CAPABILITIES: - Provisions for Gen III & Gen IV cam & knock sensors & valley covers - Cam tunnel will accommodate stock through oversized 60mm roller bearing cams (includes cast-in lock screw pads) - .842” lifters standard with material available for oversized lifter access (accepts 1.060” bushing for keyed lifters) - In the standard deck, maximum pushrod angularity = Less than 2 degrees - Includes Ampco 45 cam thrust plate and aluminum rear cover - Lifter bosses designed to clear tie bar lifter SUPERIOR OILING: - Priority main oiling, galley moved outboard for long stroke clearance - Oil filter feed galley GM “dog bone” replaced with proprietary no restriction threaded plugs - Dry sump friendly with provisions for more serious dry sump setups; includes big front & rear AN-12 side feeds - Includes provision for piston oil squirters, cast-in & machined ADDITIONAL FEATURES: - Rolled threads on all threaded holes for added strength - Gen III/Gen IV compliant with race mounts for Gen I, Gen II, Gen III & Gen IV engines - ARP main stud kit standard with enough material in castings to accommodate up to a ½” fastener - Chilled main bearing bulkheads for added strength - Optimized billet main caps & improved windage