Good evening all. I'm going to be setting posts for my driveway gate and need some help.

The gate will be 16' that I'm planning on less than 500#. Built out of 3x3x0.25 for the hinge support 2x2x0.85 everywhere else.

The soil is eastern fresno county heavy black clay that swells in the winter and gets 1" cracks in the summer.

The post will be 6x6x0.25. I'm stuck on how deep the post should go. I'm thinking 30" hole 6'deep set in concrete. Would this work?

Thank you for the help.