I just had a 383 stroke motor built for my 70 Nova.  I'm running a brand new set of AFR heads.  I can't for the life of me get the valve cover to seal on the passanger side.

I have tried cork gaskets, doubling the gaskets, and  the cork gaskets with the metal sleeve in them.  I went from a set of stamped steel covers to a set of Billet Specialties aluminum covers.  I just can't get it to seal up.  I can't seem to find any defects on the mating surface or any obstructions interfearing anywhere.

Has anyone ever had this issue?  Does anyone have any tricks I don't know about?  I have never had this happen.  I'm just about ready to pull the dang heads off and send them back.

Any help would be greatly appreciated.

JB    

I've got the same problem on a brand new set of 197 cc.Canfield heads.And I am using Billet Rail Fabricated Alum.valve covers.Whats up?  

Sometimes this is caused by porosity in the casting, where the leak is thru the casting just below the gasket rail rather then between the gasket interfaces.

Bogie

Are you using hold-down Tabs? I always have problems with sealing if I dont.