I'm looking for a low to mid-time IO-520D to put in a 1964 185B. It is a new to me aircraft and she has the light case and non-VAR crank with a few cracks (less then 2 inches) on the dogbone. What is everyone's experience with this? The cracks have been marked and we are watching them with no movement in the last 25 hours of operation.

Anyone out there upgrading to a 550 that still has time left on their 520? Keeping my eyes open for any options besides a factory reman as it is not in the budget at the moment.