[68GMCCustom]

Interesting....but the World Products Warhawk aluminum block has crank clearance for a 4.50" stroke...and the RHS LS Race aluminum block's raised cam centerline allows for accommodations for up to a 4.60" stroke.

I'll probably be satisfied with the GMPP LSX standard deck iron block, and about 427ci or so.

Warhawk specs:

TECHNICAL SPECS

Material: A357-T6 aircraft aluminum alloy
Deck Heights: 9.240" OR 9.800" (.600" minimum deck thickness)
Motor Mounts: LS1 and early small block Chevy
Head Studs: Provisions to use 2 extra studs per cylinder (optional)
Bore Sizes: 4.000" and 4.125" (w/.100" dry sleeves & .300" support
Cam Bores: Can be machined up to 60mm
Stud Holes: Counterbored to eliminate distortion
Components: Accommodates all standard GM LS-series
Oil Systems: Can accommodate dry sump (scavenge p/u at rear)
Crank Clearance: 4.500" stroke
Main Caps: Billet steel C5R-style with 200,000 psi ARP fasteners
Lubrication: Priority main (feeds crankshaft first and top-end last)
Weight: Approximately 130 lbs. with sleeves

worldcastings.com/products/warhawk-ls-aluminum-block

RHS LS Race Block specs:

Designed from heavy-duty A357-T6 aluminum material
Siamese cast bore walls (4.100” – 4.165”) with press-in spun cast iron liners
Available in standard (9.240” or 9.250”) & tall (9.750” or 9.760”) deck heights with beefy deck thickness (.500” standard/.750” tall deck); standard (5.87”) & tall (6.38”) deck cylinder sleeves available
Extra long liners for standard (5.87”) & tall (6.38”) decks
“Long arm friendly” design – Accommodations for up to 4.6” stroke with standard rod pin diameters (2.100”) & oversized 60mm camshaft
Designed for clearance – side oil galley moved outboard & engineered rod clearance come standard
Raised cam centerline (.388”/9.86mm) to allow larger stroke; 2 extra links in the timing chain – Timing sets available from COMP Cams®
Bay-to-bay breathing improved with increased side window
area versus LSX & LS7
Significantly increased windage passage area under bores & around caps over LS7/LSX engines
6 head bolt design with full water jacket around the cylinders (based on LS7 design)
Extra large windows in valley for access to inboard “6th” head bolt
Main Cap surface area maximized at mating surface & large fillets from cap to cross bolts for added strength

racingheadservice.com/lsblock/BlockSpecs.