In theory it will not matter. But in reality it will make a difference.
The closer the ground is to the starter means that the distance the "load" has to travel. More distance away from the stater the greater the resistance (load). That said, if the wire and connections are in great condition it would work fine. You want to ground to the motor as compared to the exhaust manifold as the manifold may be cast iron and may have gaskets separating it from the engine. If so, then just the stud you bolt to caries the load.
Bottom line is, the distance is not going to be a problem as long as you connect to the block and not a bolted on part.