Hello! I'm attempting to help out my brother in law with installing his deck. He went down to the deck super store and got them to make him plans. Which he submitted for permit. The plans included post locations. He dug the post holes below the frost line and then I helped him fill them with concrete. Thinking we where all set to go we started the framing from the far side. As soon as I set the first Drop beam we knew that the other end of concrete caisson's where higher than the drop beam. Roughly 4 inches higher to be exact. The drop beam is suppose to be a 2x8. Attached is my best attempt to draw out the problem. Digging down at the one end will change the drainage plain of his back yard. the yard is basically a V and the deck sits close to the middle of that. The red arrow is pointing at the problem. So since the caisson's are already in is there anything we can do? from a level line down from the bottom of the deck frame there is only 4.5" of space. So my only thought was put in a 4x4 for the drop beam and then level it up, but looking on the internet it seems as though the horizontal load of a 4X4 isn't enough. Any ideas? Thank you for any advice you can give.