if i might make a suggestion, that is very cost effective, stops the dog from digging under, and makes for easy access with the mower, when you put in the new post, get 2 extra bags of concrete, and mix them fairly dry, then dig a slight trench about a foot wide across hte gate and pour a rounded up curb underneath it, ( a small "hill" of concrete from one side to the other, when the gates shut, no digging and less crawl space, when its open, an easy to drive over pad for the mower.