valve cover leak

[chevyconvert]

Attempted to fix the passenger side valve cover leak on the 440 today. It's obvious that this has been a problem for a while on this car by the  lenght of old burnt-on oil trail down the length of the new passenger exhaust.
Anyways, attached the new Fel-pro rubber-coated fiber (best?most $) gasket to the thouroughly cleaned cover. Cover flange seemed true, checked it with a straight edge.
Thought i found why others had failed...the rear stud head hole was stripped. Replaced with a longer stud and new nut which I believe worked.Did not over tighten the nuts.
 took everyones advice and used zero gasket sealer between the head and gasket. 
Fired it up and it leaked in the rear corner. Snugged all the bolts more gradually to where it appearred to be
holding. Took her for a 5 mile short easy drive to get gas. Got home and oil was everywhere, inner fender wells,around fuel pump, and running down the heads back to the exhaust for a fresh coat.Way wosre than when I bought it a month ago.
Questions: 1.The breather on the passenger side that does not come off (?)..how do you know if it's working?
2.Is there something that could be causing excess pressure under the valve cover? the drivers side is fine.
3.The heads flange seems like a fairly rough casting. it's obvious I'm going to have to use sealant. Is there a consensus on which is best?
4. Any other suggestions...these things are
Hopefully I can get some info from you guyts tonight so I can try again tomorrow.
Thanks in advance

[Chryco Psycho]

well I use Peramtex Ultra Blue or Ultra Copper   it has high oil resistance possibly try a softer gasket like cork or neoprene rubber   the breather does come off but you should be able to blow into it , bad piston rings can cause excessive pressure in the crankcase

[chevyconvert]

Thanks chryco. I was plenty frustrated when i typed this post. Hope it didn't show too much.

So you'd use one of those sealants on both sides of the gasket?

I don't understand how bad rings raises the pressure
anyways, if the pressure was high wouldn't the excess pressure go out one of the 3 breather hoses?
Whatever this possible bad ring condition is, what would other symptoms be?

[Chryco Psycho]

if the rings do not seal well the compression pressure will bypass the rings & pressurize the crankcase

[MEK-Dangerfield]

A have a problematic valve cover on the passenger's side of my 440 too. I used RTV on both sides of the gasket. There appears to be an area on mine by the lower bolt hole back by the firewall where the the area is a little rough. Hang in there, I know your pain.
 

  Mike

[chevyconvert]

Thanks Mike..misery loves company   

[miketyler]

CP - if his problem was rings letting PSI slip by, wouldnt he see some cyl compression loss?

Also, would a PCV valve setup on his valve cover better reduce crank case pressure since it would be sucking pressure back down the manifold? I need to install either a breather or PCV setup on my cast MP valve covers soon and was wondering what the benefits were either way

[Chryco Psycho]

yes you will see compression loss
He is using a PCV valve , you really need both a PCV valve on one side & a breather on the other side of the engine