What you are showing "looks" about right. Sometimes the rubber does take a bit of "finagling" to get it to set right. Here is a link to a cross section of the mount. (scroll down untill you get to figure 20)
http://chevy.tocmp.com/1948_51truckshop/51ctsm0613.htm
The lip of the bottom metal plate is "supposed" to support the top plate at the outside bolts or so I have been told. Wait a minute and somebody will come along who can explain it better than me.


Always get a 2nd opinion, especially if I am the source of the 1st opinion.