Dart 31223354 - Cast Iron Big M Sportsman Engine Block Chevy Big Block 10.200 Deck, 4.250 Bore, Ductile Caps Dart engineered the Big M to be the strongest, most reliable, and easiest to build big block on the market. With deck heights of 9.800” and 10.200” and bore sizes up to 4.600”, the Big M gives you the versatility to build a wide variety of engine combinations. The Big M is fitted with Billet Steel 4-bolt main caps for ultimate bottom end strength. The Sportsman block is fitted with Ductile Iron 4-bolt main caps.

Material: 

Superior iron alloy

Bore: 4.250" (unfinished)

Bore/Stroke: 4.625" x 4.750" (max recommended)

Cam Bearing Bore ID: 2.120"

Cam Bearings: Specially-coated & grooved with three oil holes #32210030

Cam Bearing OS: +.010", +.020", +.030"

Cam Bearing Press: .002"

Cam Plug: 2.215" shallow cup

Cylinder Wall Thickness: .300" minimum @ 4.625" bore

Deck Height: 10.200"

Deck Thickness: .625" minimum

Fuel Pump: Mechanical pump provision

Fuel Pump Pushrod: STD BBC

Freeze Plugs: Press-in cup plugs 1-5/8"

Lifter Bores: SBC .8427" to .8437" +.300" taller Gen V, VI style

Main Bearing Size: STD. BBC

Main Bearing Bore: 2.937"-2.983"

Main Caps: Ductile, 4 bolt, center 3 splayed

Main Cap Register: Deep stepped register on each side (no need for dowels)

Main Cap Press: .005"

Oil System: Wet sump, main priority oiling (can use dry sump)

Oil Pump Shaft: BBC shaft with wet sump

Oil Filter: Stock location

Oil Pan: Standard Pan rails

Rear Main Seal: Standard 2 piece Felpro 2918

Serial Number: On main caps and left front

Starter: Standard BBC Stud

Hole/Head: Blind holes 

Timing Cover: Can use stock stamped steel or plastic

Torque: All 1/2" bolts 105lbs

Weight: 4.250"-250lbs