Racing Head Service (RHS) 54901U - LS Block, Tall 9.75" Deck, Ready To Hone To 4.120"

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