If it is a Keystoker 90 he can easily add take off the top either 6 inch or 8 inch and supply the upper floor easily. I bought the kit from Keystoker and cut the hole in the top and tack welded the collar no problem. Call them they will tell you the set back dimensions, I was awfully carefull, and it was a piece of cake. Hardest part was retrieving the cutoff piece down the inside back of the stove in the plenum area. A magnet from and old hard drive was my friend.