what I did was not as fancy as what dsraven shows.
the tailpipe is 3"
the silencer is 2" x about 16", the end towards engine is capped, the fat end of the silencer is a piece of 3" slit and rewelded so it is 3" OD and slides into the tail pipe, a circle of plate fills in between the 2" and 3" part of the silencer. So all the exhaust has to go through the small holes and then exit out the end of the silencer. There is no steel wool or other baffle material.
end towards engine:
view inside from tailpipe end
it is trimmed flush with the tailpipe and held in with 2 sheetmetal screws