I need to run 3" pipe from my new stove through an existing hole in my wall. The existing hole was from a wood stove that had 8" pipe running through the wall. On the inside wall I have a dry-stacked stone wall. The problem I am faced with is that the stone wall increases the distance from the inside to the outside that I have to run through the wall. Thus, the wall thimbles that I see online seem to be too short (10 in. max.). Any solid (but nice looking) suggestions on the best way to utilize the hole would be appreciated. I don't have the exact measurement at my fingertips, but I need to go through about 8 or 10 inch block plust maybe 7" of stone wall. Thanks in advance!