So I currently am running a catch can on the 5.3L, but I've seen a couple of videos where guys have blocked or plugged the pcv,
and just threw some breathers on the valve covers. Is there any problem with doing this?
1. Doubt anyone here at this forum is part of your city or state gov't.
That said, don't think it's technically legal to block or plug the PCV, but it's also mechanically a bad idea.
Most people who added breathers back then usually didn't block or plug the PCV.
You REALLY don't want pressure building up in the crankcase / oil pan area.
(Ideally, you want a very mild vacuum, actually ...)
2. Motor oil vapor cooling underhood is vaguely analogous to cigarette smoke accumulating in / on everything in a room / apt / home.
Eventually, even though some of it'll come off on your finger, it's impossible to truly clean.
3. You're already using a catch can, which puts you well ahead of many who don't,
especially if the catch can is actually allowing the lighter vapors back into the pcv,
and catching the heavier stuff so you can keep it out of the engine and be rid of it.
(Come to think of it, has anyone ever done a used oil analysis of the stuff caught in the catch can?
Bet it'd be food for thought ...)