About ready to purchase my first woodstove. Going to install in existing fireplace using a 6" flex liner that will run directly down into the top flue mount on the stove. I'm planning to install a 1 piece blocker plate (sheet steel with flanges around sides) at the top of fireplace opening (just below where the damper was). With the stove that I'm planning to purchase (Jotul J400) and the planned position of the blocker plate, I'll be left with ~3.5 inches of vertical clearance. Can I crimp the end of the 6" flex liner and fasten directly to stove or do I need to use a connector? If so, any ideas on how to install with such a limited space/height?