Tom,

I'm having an IO-550 built for my Legacy at Performance Engines (formerly Performance Aero Engines). Very cost effective over new and the engines are balanced to within a gram, flow matched and feature their own forged pistons. I could not be happier with my choice. They also send the new TCM cylinders out to ECI for the Ceraminil treatment. (A must for Continentals).

Stuart Featherstone is the one to call if you have any questions for Performance engines at 909-763-5228.

Hope this helps. Contact me if you like,
Don Barnes
Legacy 198