Thanks to everyone on posting their mods, I have done a lot of them and added some of my own. They are:
1) Put the gasket around the door
2) Bought a 12" cast iron skillet and filled it with ceramic briquettes
3) Filled the water pan with Ceramic briquettes also
4) replaced the chip pan with the basket (I still put the cast iron skillet on top)
5) Added the masterforge chimney
6) Add a air damper on the bottom
7) Use 18" amps tube for smoke ( I use pecan)
8) Bought a 4' x 6' welders blanket and draped it over the smoker
After making mods 1, 2, 3, and 8 the temperatures really stabilized. It can go for hours without having to tweak the temperature knob. When I used the water pan and the water started to evaporate, the temp would spike
So here is my question to you guys, the reason why I did mods 5 -7 was because after I would smoke ribs or boston butt for 3 hours or or longer the bark would taste bitter (not a good smoke taste). Of course I did a Google search and it told me it was the air flow, etc. I first changed to the AMPS and was looking for thin blue smoke (my smoke from the chunks in the skillet was thick white). The AMPS did produce less smoke and it looked lighter maybe blue, but I still had the bitter taste.
I then added the chimney and still had bitter taste. I did notice better looking smoke after I added the damper on the bottom but I am still getting bitter bark. I changed rubs and even made my own. Do you guys have any suggestions?