The 6.4L truck engine is a real stinker to add a catch can, especially if the warranty is a concern. The reason is the pcv system is not routed outside the intake manifold (like nearly every other engine in the history of engine building). The closest the vapor path gets to being easily accessible is the pcv valve itself.
The valve is all of about 3.5" long with a dia of .5". Not exactly a lot of room to manipulate the vapor path to a catch can. Add to that the regulating of flow and it becomes a challenge to reroute.
With that said there are some existing possibilities: forum member
@crazykid1994 did an intake swap 5.7 to 6.4 and took no sheet from anyone or anything and rerouted the vapor path outside the intake manifold, passing through a catch-can. He has a build thread for his rig with details and pics included. This does require a couple new holes in the intake manifold. But probably the fastest path to a catch can at the moment.
After some discussion with crazykid, and spending a good portion of my life over the last 6 months, I have actually prototyped a new pcv valve for my truck that replaces the OE valve and gives access to the vapor path. The new valves uses the OE check valve and o-rings which slip right off the OE and and onto the new valve. It requires no further modification.
This is basically a pcv valve with two ports. To use it, one merely has to twist the OE Valve out, remove the two o-rings and the check valve, apply these items to the new pcv valve and twist it back in. Hook the two hoses up to the ports, mount the catch can and literally done.
If the truck needs to go for service, the new valve comes out and the OE valve back in, if it's a concern.
It will be smooth as soon as I get all the stupid sheet worked out of the prototype. It's a story in itself and I won't beat it up here. I have run a couple thousand miles successfully separating oil and air in the catch can.
I have to make a change to the clocking position of the two stops on the valve lid with the locking gear on the valve column, and then it would be ready for a couple people try it if they want. Or wait till I run a couple more thousand miles. But my latest valve has been working, even with the stops improperly located. So I can guarantee it to work if your intake is the same as my 2016.
There maybe others who are working a bypass system as well. I have heard but not seen or know any other details. Maybe a Facebook fella and maybe a different part.
I had my engine apart on a top end rebuild recently and it was nasty with the build up from pcv system. I won't run without a catch-can if I can help it.
A couple of the protos shown:
