Petersen used to have a list of airframes tested and failed but I can't
find it.
You might email them. They do support some O-540 models (this is what
you have
right?) but the airframe isn't listed.

My O-540 is approved for car gas.

It's got to be the low-compression version to be eligible.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"