If you are ordering a Moser Engineering rear end there is no need for you to purchase the housing bushings for the rear upper control arm(s).
When ordering a Moser Engineering rear end for a vehicle with rear upper control arms that have the bushings pressed in to the housing (ie. 1964-1972 GM A-Body, 1978-1987 GM G-Body, 1979-2004 Ford Mustang, etc.) your new rear end will come with bushings already installed in the housing. All Moser housings for the 2005-2014 Ford Mustang come with a spherical bushing installed in the upper control arm mount.
If you are ordering a Strange Engineering rear end the housing bushings are NOT included.