A (forged) 340 Crank is Not a (forged) 273/318 Crank?

The 340 had lightening holes to compensate for the heavier rods it used. you can make a 273 forged or a 318-3 forged truck crank (even a 318 poly!) 340 spec by balancing to heavy rod specs. The 340 forged cranks PAW sold were poly cranks drilled to 340 specs.