I'd like to start a thread on mods for the venerable 300S - both experimental and certified. Hopefully those of us with certified versions can swap approved 337's. My 300S has no mods but will probably swap the battery for the Odyssey SBS J16 this winter. I have approved 337s from other airplanes.
This is what I know of so far but almost all are on experimental 300S's:
- Larger rudder
Elevator (? - mentioned by Maxu)
Plenum with updated cowing intake (Teebird Enterprises is working on a 337 for this now)
-25 MT prop
Air barrier put in just in front of the tail inside the fuselage to eliminate the draft
Flat spade (replaces old version that has dihedral)
SE Aero does have a one piece bottom fairing for the old 300L's that supposedly will fit a 300S. But they said Germany doesn't want to do the engineering for the mod on certified 300S's.