⚠ No shipping to California due to CARB regulation.

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, 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.

RHS® LS aluminum blocks, available in standard or tall deck, feature 55 mm cam bores, 0.904" lifter bores, raised cam and outboard oiling for 4.600" stroke clearance. CT-scanned for precision, the base for high-horsepower builds.

• P1 MFG main stud kit standard with enough material in castings to accommodate up to a 0.5” fastener
• RHS LS Block, Standard 9.240" Deck, .904 Lifter, 55 Roller Cam Bearing (Machined Only)
• Gen III/Gen IV compliant with race mounts for Gen I, Gen II, Gen III & Gen IV engines
• 6 head bolt design w/ full water jacket around the cylinders (based on LS7 design)
• 2 extra links in the timing chain – Timing sets available from COMP®
• Raised cam centerline (.388”/9.86mm) to allow larger stroke
• Rolled threads on all threaded holes for added strength
• Chilled main bearing bulkheads for added strength
• Optimized billet main caps & improved windage
• .904” lifters standard