Here is what I have...I build a new home and intended on installing direct vent gas fireplaces on the main floor and in the basement. The gas unit is installed on the main floor but I have decided to install a wood insert in the basement instead. The two units will be directly above and below eachother. I have a chimney chase that is 78" wide, 32" deep, and approx. 37'tall from basement floor to peak. I have a Buck 27000 wood insert I'd like to install in the basement. I plan to run Class A double or triple wall SS pipe up the chase and out the top. I'm going to lay block around the back and sides of the chase to eliminate exposure to combustables around the insert itself. One problem I have is the gas insert on the main floor is directly above where the wood insert will sit. This will not allow me to run the chimnet from the wood insert straight up the chase. I have room to route the chimney pipe around the gas unit then back to the center of the chase, is that feesible? I would have to 45 over, go up about 6', then 45 back to the chase center. My next question is will a chimney that tall draft ok or will i need a draft fan? My third and final question is what size chimney pipe should i use, 6" or 8"? Please give me some advice...I want to do this safe, correct, and with no regrets when it's done. Thanks!