This is a pier mount I created for use with my EQ3-2 Pro mount. It fits a 95x95 end (see attached picture) which I have mounted on a 95x95 pole that's anchored by a concrete plinth (also depicted as an attached picture).

It's easy to mount - fasten the EQ3 head with a bolt and washer in the middle. Make sure it's tightened well enough - you can't tighten it afterwards without removing the entire setup.
Fasten the adapter plate with attached mount head with bolts and nuts (nylocs or lock washers preferred). Enjoy!

P.S. I chose to contra-lock my nuts.