Hello, I am currently in the process of building my first smoker. The pit is 20" diameter x 40" lg. made from rolled 10awg steel. I am going to mount this on a small 40" X 48" (kit) trailor, just for ease of movement. Check out some of the pics of the build below. We are building 3 of them. This is the pit after we got the end caps welded on and the butt seam on the bottom side. This is once we get the fire box end caps welded on and the butt seam on the bottom side. All 3 of the smokers (fireboxes are not attached)... We are doing 2 smokers like this...they will have front and side shelves and also will have wheels. Here is a 3-D image (I am a drafter) that I modeled of what my rig will look like when I am done... I got doors rolled out to so I plan on using my cut-out as my RF convection plate. I also just designed my own trailor wheels, they do not actually look like this. lol. One question I have is, does it matter which side of the pit the firebox is on? Typically on store bought smokers, I see them on the left but in most custom builds, I see them on the right? Is that just a preference thing or does it have meaning behind it? Any input is appreciated as this is my first build.