Rebuilding my '68 350 and want to get some nicer valve covers. Found a set with no holes and or grommets. Can I use them without punching a hole for the PCV valve? Any alternatives to ventilating through the cover?
Thanks

 

Sure. Do like the 70-72 W-30s and put the PCV valve in the valley between the runners of the intake.

 

Better be a place for the air to COME IN also. Not right next to the exit, preferably. Also, the fumes flow the other way at times, so that air entry should connect to the air filter housing.

This may not be the ideal candidate for a system to abandon to "tidy up the engine compartment."

 

It's still going to need at least one of the valve covers punched out for a needed breather, or maybe the oil fill cap has to be changed to a ventilated breather style If possible, if you do not want to punch out a valve cover. I don't believe just running a PCV valve alone will work, there has to be a way to introduce air in for the PCV valve to pull, or the setup will create a high vacuum in the engine and suck oil and/or oil vapors into the engine. The W-30's actually used two breathers plus the PCV valve setup in the manifold like Joe mentioned.
(I see Octania beat me to it)

 

You are both correct, you would want a breather cap on the oil fill tube, a la the 1967-earlier cars.

 

While we're kinda of on the subject of PCV valves, does the W-30 PCV in the intake have any type of baffle under it, or is it a "dead" area that does not have much in the way of oil and/or oil vapors that could be sucked up.

 

Should definitely have a baffle on the vacuum side. The motion of valve lifters can toss oil in a variety of directions.