That can be fixed, but the question will be is it worth the cost. What kind of block is it? If its a 428, it would probably worth the repair. If it's a 390, I think you'd be better off getting another one.
To fix that you will need to find a cast iron welding shop, get a patch welded in, and then get the block remachined. The welding operation will warp the block surfaces, so it will probably have to have the oil pan rail re-machined and also the main saddle align-honed.