So, I have a slow oil leak out of both valve covers, so I was going to try changing the gaskets. But before I start pulling stuff apart I was wondering just how hard are the gaskets to take out? Are they just pressed in or do they have some kind of adhesive behind them?

 

On the 460 from the factory they were cork & most of the time are dry & britle & fall off. Have you tried tightening the bolts?
But I see you have Jasper heads I don't know what or how they use for gaskets. But I assume they will come right off.
Craig

 

I'm in agreement w/ Craig- if someone else worked on 'em, you never know what they used, or didn't use for that matter.

I suggest that since they are leaking, it's not likely they used any adhesive, but that's not concrete evidence by any means. About all you can do is pull them off and see what happens.

It's probably not anything a wire brush and emery cloth won't take off.

 

The heads needed to be rebuilt last summer due to a blown head gasket, so I took them some where to get them done quick...(which took 2 weeks anyway). I went back and checked the receipt and nothing was mentioned about the gaskets, and I didn't think anything of it since they were fine with no leaks for the first month.

After about a month and a half I noticed the driver side had a slow leak that was only forced out when the truck was running. So I did tighten the bolts a little each time it ran for about a week, and now it turns out the passenger side is leaking as well. They are now leaking enough that I had to add 1 1/2 quarts over the past 2 weeks.

When the valve covers were taken off to rebuild the heads I took them to clean them up and paint them, when I was doing that, the gaskets seemed they were made of rubber. Did some have with rubber instead of cork? Or could they have been changed before?

Oh, and while I was painting them I did notice that one of the gaskets was kind of flattened on one of them. I know now I probably should have done something about it then.

 

The newer 460 had a rubber o ring gasket theres a groove around the edge of valve cover plus the valve covers are aluminum and bolts tighten through top of valve cover

 

Aftermarket gaskets are available in rubber or cork. I'd suggest getting the rubber ones, as not only do they seal better, but they're easier to install and also have brass inserts that help keep the valve cover evenly spaced.

The key thing to remember is that you don't overtighten the bolts. Even a couple foot-pounds over torque can cause the valve covers to warp enough to leak.

 

Sounds like what I have. I just ordered the gaskets today, hopefully I'll have time to get them on by the weekend.