I'm curious about what that would do… can you explain what you have in mind?
Bit of an "inside" joke (which Dave "gets!").
With nothing to do, search, "PCV Valve Mod."
The implantation of a check valve in the crankcase vent line was SUPPOSED to deliver increased power, better fuel economy, decreased oil consumption, enhanced ring seating, improved engine compression braking, and . . . a few more advantages I've forgotten. (Purported operational mechanism: Consequent vacuum in crankcase responsible for all improvements; flaw (among others, maybe); no crankcase vacuum (air pressure lower than ambient) ever measured, except momentarily during severe deceleration.)
Thus, as Dave says above . . . the PCV valve did NOTHING measurably constructive!
Yet . . . the mode was fiercely defended by certain True Believers.
Perhaps the PCV Valve Mod isn't the only modification wanting a, "leap of faith!"