BluePrint Engines BPP12110361 LS Block, 9.705 Deck x 4.125 Bore

When your LS build demands serious displacement, you need a block that’s engineered to go the distance—and this LS-compatible foundation is built to stretch all the way to an impressive 468 cubic inches. With reinforced architecture, thick cylinder walls, and precision-machined surfaces, it delivers the rigidity and reliability needed for high-horsepower, high-rpm combinations. Whether you’re assembling a torque-rich street monster, a boosted track bruiser, or a no-compromise stroker setup, this block gives you the headroom and confidence to push your LS platform far beyond stock limits. Big inches, big power, and rock-solid dependability start right here.

• 9.705 Deck x 4.125 Bore
• SIAM
• Steel Billet Main Caps
• 6-Bolt

Cylinder Bore (Rough):

4.120" to 4.122"

Cylinder Bore (Max):

4.185"

Cam Bearings:

Dura-Bond CH-25

Cam Bearing Bore ID:

#1 & 5: 2.3482±.0005", #2 & 4: 2.3285±.0005", # 3: 2.3088±.0005" w/ stock available to bore up to 2.362" (60mm)

Camshaft Position:

Stock OEM position - 4.885" to Crank

Cam Drive / Timing Set:

Accepts OEM style

Cam Retaining Plate:

BluePrint Engines P/N:18111370

Cubic Inch (Max):

468 in3

Cylinder Wall Thickness:

.210" @ 4.185" Bore

Cylinder Skirt Length:

6.210"

Deck Height:

9.705" +.005/-.000"

Deck Thickness:

.600"

Freeze / Core Plugs:

1 5/8" dia, BluePrint Engines p/n: 10110016 (Qty 8)

Head Bolt / Stud:

6 Per Cylinder

Head Bolt / Stud Threads:

M11 x 2.0 2.36" Deep (+M8 uppers)

Lifter Bores:

.8437 ±.0005"

Lifter Retainer (If not using tie bar lifters):

GM LSX Style

Main Bearing Bore (Line Honed):

2.7509 / 2.7514"

Main Bearing Caps:

BILLET STEEL, OEM style, 6 Bolts Per Cap

Main Cap Bolts:

Inner: M10 x 102mm, Outer: M10 x 84mm (stud), Skirt: M8 x 24mm

Main Fastener Tensile Strength:

180,000 to 210,000 PSI

Material (Block):

EN-GJL-250 Iron

Oil System:

Priority Main Oiling System w/ Center Crossover

Oil Pump:

OEM

Oil Filter:

OEM (in Oil Pan)

Oil Pan:

OEM

Oil Gallery Plug / Barbell / Dogbone (rear):

OEM

Piston Oilers / Squirters:

No

Rear Main Seal:

Accepts OEM Style Rear Cover

Starter:

OEM, Passenger Side Only

Stroke (Max):

4.250"

Timing Cover:

OEM

Valley Cover:

OEM

AFM/DOD Compatible:

No

Approx. Weight with Main Caps:

230-250lbs