After ripping off the emissions I'm left with two nice holes in the valve covers. I know I can get breathers for them but can't I just block them off all together with a plug or do they need to breath?

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'89 IROC, custom 600cfm Holley carb, Street Dominator Intake, Flowtech headers, no cat, Flowmasters, no emissions (smog pump, charcoal fillter etc), remote starter solenoid, push button start, getto sound system, none leaking sunroof

 

Put the PCV valve back into one of the holes and put a breather into the other one. PCV is a Good Thing.

 

Get them fast. You do not want that pressure building up.

 

DO NOT PLUG THE HOLES!!!!!!!

If you do, you'll be very, very sorry. Go to pep boys and buy a breather for the passenger's side and a pvc for the other side, and do it fast. Don't drive you car anywhere with the valve cover holes plugged.

You'll build up so much gas and condensation in such a short time, you engine will rot from the inside out!!!!!!!!!!

 

So that would be a no to blocking the holes then eh? Good job I asked before I just wnet ahead and did it... thanks guys