Dart 312233444 - Cast Iron Big M Sportsman Engine Block Chevy Big Block 9.800 Deck, 4.500 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: 4.500" (unfinished)
Bore/Stroke: 4.625" x 4.500" (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 @ 4.624" bore
Deck Height: 9.800"
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
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: 4.500"-260lbs
