I am going to replace the Vermont castings encore that was in the house that is uncontrollable due to neglect by the previous owner (don't trust unit). Gonna go with a jotul f400 or pacific energy alderlea t4. The existing old chimney was relived in 95 with 8" and I am thinking do I just replace the liner since it is 8 I am not against replacing the liner as I want to do it correct. Thoughts?