There are a couple outfits working on it. I have a friend that's been
following the subject. I'll try to get the names for you. Last I heard,
one outfit that was quite a ways into the project was having trouble with
Hartzell. Something about prop vibrations, so the STC would have a
power/rpm limit to be observed. They thought that would solve Hartzell's
concerns.
Jim

"Juan Jimenez" wrote in message
...
Anybody know if there are any STC's for installing high compression
pistons
on an AEIO-540?