340 8 bolt crank info wanted

The new Mopar Performance cranks I have seen did not have any of the crank throws drilled for balance. So similar to forged 318 or forged 273 crank but unlike the 340’s forged cranks which had two of the rod throws drilled through at the factory. When your motor was built, if for example they used the stock damper and flywheel and did not rebalance the assembly this could cause it to be unbalanced. If it was assumed the new MP crank had the same weight and weight distribution of a 340 crank that could cause it to be out of balance.

Many variables to consider.