I have a twenty year old ranch with job-built W trusses installed with a continuous 2x8 ridge. Top chords are 2x6, the remainder 2x4. I want open a section up and somehow rework the existing trusses to allow for a cathedral ceiling. The open space above the bearing walls is approximately 15 inches, so-called energy trusses in this area. Any suggestions other than tearing everything out and starting from scratch?