Jim- I thought Giubo bearing was the correct nomenclature for the rubber donut mount at the front end of the driveline.
As far as the center bearing is concerned, IAP shows it as two pieces, a rubber "D", laying on it's back that snugs up into the tunnel, with a race that rides inside it. (Pressed in?). Then the whole assembly is supported, but not attached to, a plate with two holes in it that fits over two studs hanging dawn, and gets nutted into place. I bought the "D" peice and the bearing that rides in it. HTH.