A few more hours on the cooker today let me get the exhaust welded on and the gaps next to fire box filled in.
A view of the exhaust pipe from the front, I used a square 6X6 tube. I will still be putting a rotating cover on the exhaust so I can keep the rain out.
Here is a view of the exhaust from the firebox side.
Here is a view looking into the firebox from inside the cooking chamber.
My cooking chamber is 30" wide, but I only wanted my firebox to be 22" wide, so that left me with around a 4" gap on each side. So in this shot I have welded in the inserts/patches on each side of the firebox. You can also see the bottom of the exhaust pipe, once the cooking racks are installed the bottom of the exhaust will be in between the two racks. I did this because I wanted to hold some of the heat and smoke in the cooking chamber before it escaped. On my previous build I put the exhaust at the top, and I feel like a lot of my heat and smoke are escaping without doing much work.
Here is a exterior view of one of the sides insert/patch. I had been dreading this step but it turned out to be pretty simple.