Installed new rear end, bleeding brakes Q

If you have a 2 line resivoir and just the one section is now empty then you'll only need to bleed the rears. Its possible that no pedal pumping will be required either. Just let it run until you have pure fluid (no bubbles) at the bleeders. if both sections of a split resivoir are empty the perportion valve is allowing a blend and all will need bleeding from right rear to left front.