as in centered where you want it. before you drill, you need to make sure both trucks are the exact same distance away from the center and edges of the board, as well as ensuring the trucks are on straight, otherwise it will be beyond squirrelly. Maybe take it to a skate shop to see if, for whatever reason, they have a mounting jig. ski shops have jigs for bindings, and since it is the same concept, you may be able to use a binding jig to mount them. otherwise you will need a ruler, straight edge, pencil, and a whole lot of patience haha