Dart big block Chevy Big M Sportsman 10.2" deck 4.5" bore block #3123454

Dart BBC Big M SPORTSMAN BLOCK #3123454

Main Caps: Ductile Iron

Standard Main Bearing Diameter

Deck Height:10.200

Cylinder Bore Diameter:4.500 (made to hone to 4.500)

• The Dart Big M Sportsman block was designed to be a more affordable version of the highly popular Big M.
• The Sportsman block is fitted with ductile iron 4-bolt main caps, and features a redesigned lubrication system that oils all of the main bearings before the lifters for extra reliability.
• Dart added two slotted head stud bosses on both sides of the lifter valley so you can use studs instead of hard to install bolts to take the place of the "missing head bolts".