School me on balancing an engine.

Well I got one fer ya'll then. I just bought an Eagle steel 4 inch stroke crank, forged aluminum, dished pistons, Eagle I beam rods, all with ARP hardware. It was all sold through Indy as a kit. Before they shipped it, I had them internally balance the crank. I have a balancer that has the removable counterwieght, and will go with a non-wieghted converter. My question is this..... I thought the crank would have mallory slugs in it, they just drilled the crank throwes. This is not what I was expecting, Is it right?