I have made hunting cranks by drilling a crossways hole low in the belly, and just behind the front hook hanger. I
determine how much ballast I need, and then subtract the weight of a .22 caliber sst ball bearing that I put in the crossways hole, so it's free to move from side to side.
It's tricky to get the amount of side to side movement right, but it give the bait a darting side to side action, when the ball is shifted from one side to the other during the retrieve, changing the center of gravity.