Got the Thrush Turbo on the slant six
Based on recommendations here and a video on youtube I went with a thrush turbo muffler. Goal was to get a nice sound without being super loud, and spending as little money as possible. Between the muffler, clamps and an extension for the tail pipe I probably spent about $45 total on this and I am pretty happy with the results.
The video makes it seem louder than it is but here's an idea of the sound you get. Pipes are factory style 1 7/8 before, and a 1 3/4 tail pipe after, single exhaust.
[ame="http://www.youtube.com/watch?v=4InkN58P25I"]YouTube- 225 Slant Six with Thrush Turbo Muffler - 1970 Plymouth Duster[/ame]