Top Gun Customz rear steel lift option

I was looking at a picture on the Top Gun website of the installation of the 2.5 inch rear steel coil lift spacer and it appears the spacer assembly is coil spring on the bottom, with isolator on top of spring and the lift spacer on top of that. My question is, the pic shows the bare steel top of the spacer, so does that mount up supporting the frame above the spring? Steel on Steel? Am interested in mounting the Bilstein 5100 on the front set at 2.8 and installing the 2.5 in the rear. Also wondering with that lift, how much of an angle results on the universal joint between the pinion flange and driveshaft. I know the 4" lift on my old 87 power ram used a inclined plane on the back lift block under the rear leaf spring to provide a little tilt to the axle to keep the degree of angle low as possible to prevent rapid wear of the universal.