BluePrint Engines BPP12110343 SBC Block, 4.125 Bore, 350 Mains

If you’re aiming to build a stout, reliable small block without breaking into exotic territory, this SBC-compatible block is the perfect foundation. Engineered to comfortably support combinations all the way up to 454 cubic inches, it delivers the strength, precision, and durability builder's demand. With thick cylinder walls, a rigid casting, and smart machining allowances, this block is built to handle everything from a crisp street cruiser to a hard-hitting weekend track car.

• 9.025 Deck x 4.125 Bore
• 2-Piece Seal
• 350 Main
• SIAM
• Ductile Cast Main Caps

Cylinder Bore (Rough):

4.120" to 4.122"

Cylinder Bore (Max):

4.250"

Cam Bearings:

Durabond GMP-8

Cam Bearing Bore ID:

2.000"+/- .001"

Camshaft Position:

OEM

Cam Drive / Timing Set:

OEM Equivalent

Cam Retaining Plate:

OEM

Cubic Inch (Max):

454

Cylinder Wall Thickness:

.230" Nominal @ Max Bore

Water Jacket Style:

Siamese

Cylinder Skirt Length:

5.800" Nominal

Deck Height:

9.025" +.005" / -.000"

Deck Thickness:

.600" Nominal

Freeze / Core Plugs:

1-5/8" x 10

Head Bolt / Stud Threads:

7/16-14 UNC

Lifter Bores:

.8437" +/- .0003"

Lifter Retainer (If not using tie bar lifters):

OEM W/Roller Provisions

Main Bearing Bore (Line Honed):

350 Main - 2.6402" - 2.6410"

Main Bearing Caps:

Ductile Cast Iron 4-Bolt Splayed

Main Cap Bolts:

7/16-14 Inner / 3/8-16 Splayed

Main Fastener Tensile Strength:

180,000 to 210,000 PSI

Material (Block):

EN-GJL-250 Iron

Oil System:

Priority Main

Oil Pump:

OEM

Oil Filter:

OEM

Oil Pan:

OEM

Rear Main Seal:

2-Piece

Starter:

OEM

Stroke (Max):

Cast in Clearance 3.875"

Timing Cover:

OEM

Approx. Weight with Main Caps:

170-190lbs