DA31223644 - DART BLOCK BIG M SPORTSMAN OEM 4.600" BORE C/IRON 4BOLT 2PC RMS BBC

BB Chevy, Dart Big M Sportsman Block, 9.800 Deck Height, 4.600 Bore, Ductile Main Caps, Engine Block

Dart Big M Sportsman Block has made building big cubic engines easy. Dart has engineered the Big M sportsman block to be the strongest, most reliable, and easiest to build big block on the market. Features Siamese extra thick cylinder walls resist cracking and improve ring seal, scalloped outer water jacket walls improve coolant flow around the cylinder barrels to equalize temperature. Four bolt main bearing caps have splayed outer bolts. Crankshaft tunnel has clearance for 4.500 Stroke crankshaft. Rear four bolt cap uses standard oil pump and two piece rear seal.