The 6.4 in the cars already have one built in. It drains back into the engine................That said, it is not necessary unless you have a high milage engine that may have a significant amount of blow back. And even then, run the engine and spray injector cleaner through the air filter. It will clean out the intake too. Or spray carb cleaner through the air cleaner with the engine running. Use the whole can. Same thing. Waste of time and money unless you are one of the cool kids with a chrome cold air intake......that is a hot air intake because it pulls air from the engine bay, where it is hot..................Leave it alone. You will get over 200k miles from it doing nothing. When it fails, put a rebuilt long block in it, rinse and repeat...............Some of the smartest people in the industry have already tested and decided there is no benifit unless it is a high performance model.Ive had catch cans on my last (3) 5.7L 1500s.
Now, Im in the market for a 6.4L and am pretty bummed one cant be added easily to it.