Dart Big M Sportsman Iron Engine Block Big Block Chevy 4.250 in. Bore
301-31223344
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Iron Blocks W/Ductile Iron Main Caps
Features:
- Ductile iron 4-bolt mains caps for ultimate bottom-end strength
- Siamesed extra thick cylinder walls to resist cracking and improve ring seal (minimum .300 in. thick with 4.625 in. bore)
- Uses +.300 in. tall GM Gen VI style lifters
- Crankshaft tunnel has clearance for a 4.500 in. stroke with steel rods without grinding
- Main bearing caps have splayed outer bolts for extra strength
- True priority main oil system lubricates the main bearings before the lifters
- Stepped main oil gallery (9/16 in. to 1/2 in. to 7/16 in.) increases the flow of oil to the crankshaft at high RPM, and front oil crossover eliminates internal oil leaks around the distributor shaft
- Lifter valley head stud bosses prevent blown head gaskets
- Dual oil pan bolt patterns fit standard and notched oil pans
- 220 BHN cast iron block material
- .842 in. lifter bores
- Press-fit freeze plugs
- 2-Piece rear main seal
- Note:
- Block parts kit sold separately - 301-32000002
Specifications:
Motor Vehicles
WARNING: Motor vehicles contain fuel, oils and fluids, battery posts, terminals and related accessories which contain lead and lead compounds and other chemicals known to the State of California to cause cancer, birth defects and other reproductive harm. These chemicals are found in vehicles, vehicle parts and accessories, both new and as replacements. When being serviced, these vehicles generate used oil, waste fluids, grease, fumes and particulates, all known to the State of California to cause cancer, birth defects, and reproductive harm.
Tools:
WARNING: Some dust created by power sanding, sawing, grinding, drilling, and other construction activities contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Some examples of these chemicals are: lead from lead-based paints, crystalline silica from bricks and cement and other masonry products, and arsenic and chromium from chemically treated lumber. Your risk from exposure to these chemicals varies, depending on how often you do this type of work. To reduce your exposure, work in a well-ventilated area and with approved safety equipment, such as dust masks that are specially designed to filter out microscopic particles.
Electrical Cords
WARNING: The wires of these products contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Wash hands after handling.