I currently have a 1986 Vermont Casting Encore Defiant wood burning stove that has a 10” Oval Exhaust that, with the use of an adapter, has been converted to mate up to an 8” Foreverflex liner. I’ve used this for the past 3 years without issue. I am now wanting to upgrade to a Vermont Casting or even a Jotul gas stove. At first, I assumed that a Vermont Casting Natural Vent (or Jotul B-Vent) natural gas stove would be my best bet however, I was informed that at best a Natural Vent/B-Vent is only 50% efficient. I was told that I should go with a DVent stove. (1) Is there a conversion kit that will allow me to use my preexisting wood stove 8” liner and convert it to work with a Direct-vent stove with either a 4” or 6” exhaust. (2) How bad would it really be to use a Natural or B-Vent set up? Thanks, Nick BTW, I currently have the old Vermont Casting Wood Stove and a brand new Jotul DV400 stove.