318 Build Combo Critique

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Yes you are correct. I am trying to get the lightest rotating assembly using factory pieces. If the forged 273 crank is a little lighter than the 318 cast crank. So with the lighter rods I'm using the machinest might not have to add any weight with the forged 273 crank. Does that make sense? And it will be a lighter overall package.[/QUOTE]

I'm not 100% sure, but I'm reasonably certain that a cast 318 crank is lighter than a forged 273 due to the fact that the metal is denser. The reasons why cast 340, 360, and cast 440 cranks are externally balanced, they just don't carry the weight.