Leaking valve covers

[Dav]

There is a very noticable height difference between the head and intake on my 89 2.9. It leaks oil. I changed the gasket several years ago and was good for about a year. Truck doesn't see much use so I lived with it.
Now the truck is about to become my only vehicle. The motor is out and I am doing other stuff to it so now's the time to fix it.
Any surefire cures besides have the gasket surface on the head cut down to match the intake?

 

[alwaysFlOoReD]

Are you asking about valve cover gaskets?
Or intake gaskets?

 

[Shran]

Have your heads been machined down at some point? Generally this is fixed by machining the intake, not the heads.

Before you go that route though, I would suggest checking bolt torque on all of the lower intake bolts. If it was removed & reinstalled at some point, and not retorqued, it may simply not be fully seated. I have found lots of loose lower intake bolts on 2.9's and 4.0's over the years.

Another question is what type of valve cover gaskets are you using? Cork, rubber, permadry? They all need a dab of RTV in two spots per side where the intake meets the heads. If it's way off and you want to fix it on a budget, use a big blob there and lightly push a gasket onto it and let it cure without reinstalling the valve cover. Once it's dry, put the valve covers back on. That way it's built up enough to fill in a gap that exists there.

I am on the fence on gasket types. I like the Permadry concept but I keep having valve cover bolts loosen up and they start leaking. Rubber may start to be my preference. Cork is good too but it gets crispy and brittle quicker than others.