Tracy and or anyone else flying with an exposed muffler...

     I am at the point of routing the exhaust out of the cowling and aft into a muffler. I am curious how much distance I need to keep between the top of the muffler, and the bottom of the fuselage. How much heat do they put off in flight? Taxi and ground run? Does the floor get hot? Would it blister paint? Should I not paint the area directly above it? Thoughts???

  Thanks in advance.

  Ben Schneider  RV7  N713R  Renesis, EC2, RD1C, GRT EFIS, Still shooting for early summer first engine start.