I just swapped out my old GM single reservoir master cylinder for a dual reservoir master brake cylinder but am confused as to which reservoir is the front and which is the rear? Someone told me that the 1/2" fitting is the rear line and the 9/16" fitting is for the front. Others have told me the front reservoir on the MC is for the front brakes and the rear res for the rear brakes...

Now I am nervous I may be plumbing this wrong...any help?
Thx guys!