RE: Element 170 ARF wood Versions are in
Mark-
I don't run an OS (I use Webra), but the going OS side-to-rear header is made by Karl Mueller.
For a pipe, run an ESD 2c 140 L9 (Central) or an Aeroslave.
Do a search on Mueller in this forum and I'm sure you'll get lots of info. Jon Lowe is an expert on the OS, BTW.
-Ron