Davis Aviation Services, Inc., now offers the STC to convert your Cessna 188 to the IO-550 with the various propeller options!
Formerly known worldwide as the "Bonaire 550", this conversion provides for the upgrade to the IO-550 engine. With either the McCauley or the Hartzell propeller option, performance is phenomenal with shorter takeoff roll, increased rate of climb, and faster cruise speeds.
Hartzell Service Center offers propeller upgrades for the Cessna 188 to accompany your existing IO-520 engine. Davis Aviation can supply this upgrade. The remainder of the IO-550 upgrade can be purchased, as you approach TBO, to complete the performance modification.