Aha, you mean the replacement has different thickness magnets. The wires from the pickup are generally placed next to the exit hole in the pickup rout, which goes to your control cavity.
If it were back to front , you'd have the pickup wires running along side of the pickup before they exit, which is not the norm. So if the thicker magnets are next to the pickup wires, then you have your answer. It is alo likely that the bigger magnets are for the D + G, but just place the wires as i said.