Dart Big M Aluminum Block 31264654 BB Chevy

Based on the Chevrolet big block V8 design, these new aluminum blocks feature extra strengthening in critical areas, increased displacement capacity, true priority main oiling and precision CNC machining. Conventional configuration that retains all production dimensions for compatibility with standard components. Features, Premium alloy: Dart aluminum blocks are cast from virgin 355-T61 aerospace alloy for superior strength and integrity. Standard 9.800" and tall 10.200" deck heights available for stroker engines. Standard 4.250" , 4.500" or 4.600" bore sizes with siamesed extra thick cylinder walls to resist cracking and improve ring seal (minimum .300" thick with 4.625" bore). Ductile iron sleeves with extra thick cylinder walls promote excellent ring seal. Reinforcing ribs strengthen the lifter valley bellhousing flange. Scalloped outer water jacket walls improve coolant flow around the cylinder barrels to equalize temperatures. Inboard valley head stud bosses improve gasket sealing. Priority main oiling system delivers oil directly to the crankshaft bearings to enhance reliability at high engine speeds. Standard BBC cam bore, other options are also available. Standard .842" BBC lifter bores, other options also available. With or without distributor provision. Steel 4 bolt main caps with splayed outer bolts for extra strength. Ductile iron or light-weight aluminum caps also available. Mechanical fuel pump boss, clutch linkage mounts, and side and front motor mounts simplify installation in any chassis. Dual oil pan bolt patterns fit standard and notched oil pans. average weight 140lbs.