This plan includes 1 auto cad drawing with full details.
This is a very quiet muffler. If you are intersted in building this muffler you should have some basic metal fabrication tools and a welder.
The stock briggs muffler is 86 db at idle while the nelson muffler is 82 db at idle. This build it yourself version is only 72db at idle!
This muffler is 14 db quieter than the stock briggs muffler.