As a side note; that vent hole is tapped for the HMMWV fording kit when engaged (switched) it applies a slight pressure to the drive-train components which in turn prevents water ingress into all vented components.Only needs the vacuum if your worried about seals slobbering. I've never replaced a CDR, there's not much in them to go wrong If it gets really gunked up you can clean it. I tore one apart to see what is in it, and there's not much to it, a diaphram and a spring. I tested every chemical in my shop on it and couldn't hurt the diaphram. there is a vent hole on the back side you should avoid getting stuff into.
Several people have run what they call a road draft tube (no CDR and a hose down under the vehicle) won't pass emission testing tho.
I can't imagine the filter and piping giving you much if any HP increase
I like the Provent setup however; an angled cut tube welded into the down pipe then plumb the road drift tube into IMO it would pull pretty damn hard on any crankcase pressure and keep the intake tubing and CAC/IC from getting coated.....I've been considering this for the Cummins.And I thought these smelled bad on the outside! Modern EPA oil for DPF diesels, you can't hardly get anything else, stinks especially after an oil change. We don't have an intercooler that oil would insulate so it really doesn't hurt to leave the CDR in place. I am considering putting a CDR on my road draft tube 2003 Cummins due to CJ4 oil stink at a stop light intercooler be dammed.