Balance question.

I just tore down a 318 with a cast crank and found a spun rod bearing. Crank wiped out. I got a forged crank that can replace it with , but I am not exactly sure what it came out of. I know its not a 318-3 truck crank.

With the stock rods and pistons, will I have to re-balance the assembly to swap over to the forged crank?