Eagle cast cranks in a 4.00 or stock are in the neighborhood of a 2050g boboweight. so if you can get your formula for rotating mass - big end and bearings- and reciprocating mass (everything else) and get it very close to 2050, you should be within 1 slug of mallory or even lightening the crank. They say cast are for external balancing but there is nothin gto say that they cant be internally balanced if the bobweight is less than the throw weight. Forged cranks are heavier by nature so they usually need to be lightened, cast are lighter so more mass needs to be added to deal with beefy rods and old OEM mopar lead like pistons.
