A picture of the pedestal would help, but take a good look through what Ram has for mounts: RAM Mounting Systems, Inc.
I'm sure you can work something up from the many options they have.
On the other hand, if you are handy you may be able to work up your own pedestal guard. They come in handy to keep visitor's hands away from grabbing your newly Ram mounted GPS and ripping it off when an errant gust sends them sprawling.
They are also nice places to mount drink holders, hand held horns, vhf's and of course plotters