DART BBC Big M Iron Block 4.250 Bore/9.800 Deck Height, Features Simaesed 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.
- Dart Big M Sportsman Iron Block
- Bare Block
- 454 Main Journal Type
- 9.8 Deck Height (Short Deck)
- 4.240 Cylinder Bore As Shipped
- 4.250 Cylinder Bore Diameter
- Finished Cylinder Bores: NO
- 4 Bolt Main
- .842 Lifter Diameter
- Standard Camshaft Bore
- 2 Piece Rear Main Seal
- Big Block Chevy
- Iron Block
- Each