I have owned every Ford Diesel engine and the 6.4 L Engine I felt was the poorest next to the 6.0L. 6.4L problems are not just a fuel hungry engine, they also like to lose turbos, crack rads, fail high pressure oil pumps, blow boost tubes, wiring problems, and in general are backed with a poor...
Chains are a cheap maintenance. Any turbo application should change every year, plus gives you a good chance to inspect and change bearings if need be.
AEM makes a durable , bendable filter for an application for front mount turbo packages. The inner filter skeleton is made of a plastic frame and it can be twisted or squished and returns back normal form without compromising air flow.