Dart "Big M" Iron Blocks BBC 4.500 Cylinder Bore Diameter
$2,579.00
Dart engineered the Big M to be the strongest, most reliable, and easiest to build big-block on the market. The 4 bolt splayed caps available, in ductile iron and steel, and the thick main webs make the bottom end the Strongest in the Industry. We redesigned the lubrication system to create a true priority main system that oils all of the main bearings before the lifters for extra reliability. Our stepped main oil gallery (9/16 to 1/2 to 7/16) increases the flow of oil to the crank at high rpm, and our front oil crossover eliminates internal oil leaks around the distributor shaft. The result: more oil at the bearings and pushrods where its needed, and less power-robbing crankcase windage. We 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.
Dart machines Big M blocks in-house on precision CNC equipment to ensure quality and to eliminate the need for expensive blueprinting.