than having breathers and blocking off all the PCV openings? I have heard that it will.

 

Not necessarily, it could do the opposite.

 

A pcv WILL BUILD POWER IF! you install it below the heads. The valve cover is the worst location, but installed below the heads, it will give much better ring seal and wont puddle oil in the head at high RPM sustained.

 

That is why the LS6 PCV came out.
On my 370 build I switched to a true LS6 PCV system and I have 0 oil consumption, plenty of power.

 

What if you completely delete the system from the car?

 

Theres pros and cons to each... If you have enough blowby to overwhelm the small PCV line, then breaters would vent quicker. If you dont have that much blowby then the slight crankcase vacuum would perform better. At low rpms, no question, a PVC will keep things cleaner, will extend your oil life, and wont make the inside of your car stink like burning oil. The LS6 PCV is a great step up from the stock system. If you want the best of both worlds, Another choice is to run the exhaust vent kit, where the breathers have a tube that goes down into the exhaust. The exhaust creates a venturi effect and pulls a vacuum through the breathers. Or you could also run a crancase vacuum pump, the added vacuum keeps the rings from fluttering and may even gain you a few extra ponies.

 

i run both... well one in the passenger valve cover and the LS6 valley. i dont have one in the drivers side since i did not want to drill a whole in my katech covers
oh yeah 800 miles and catch can is empty. but i think its also due to the covers being higher and larger