914 Case Fretting

I have an opportunity to purchase an airplane with an early 914 S/N 4418762. I have researched the issues with case fretting on these engines - most of the problems appear to be with the 912 series. My question: Is this due to there being fewer 914s or is it because the 914 series have fewer problems with case fretting? Will it be an expectation that I will have to replace the case sometime within its 1200 hour TBO? Will measuring torque on the crankshaft (per 05-50-00) give adequate notice before failure?

Thank You!