I have the P-30 MC and the back port of the MC is the rear brakes and is the larger of the two fluid lines. Do I have that wrong?
Mr. Hupy said the larger goes to the rear. JP Winger's gallery on the photo site says the larger goes to the front. Since that is conflicting info, you need to trace the line yourself. If the line with the larger connection on the master cylinder goes to the end of the combination valve that splits to the fronts, it is the line to the front.