427/435 Valve Cover Gaskets

[Charles F.]

[Keith B.]

Re: 427/435 Valve Cover Gaskets

I always had good luck with cork and with that said I was told Fel Pro stoped making cork BB valve cover gaskets

[Mark E.]

Re: 427/435 Valve Cover Gaskets

Similar threads below have good discussion about this.
The need to over tighten to the point of gasket failure may mean the valve cover is bent. Torque spec on these bolts isn't much.

On my LS5, I resorted to gasket sealer on both sides of the gasket to stop it from leaking. Not a big deal with a hydraulic cam, but inconvenient with your engine.

[James G.]

Re: 427/435 Valve Cover Gaskets

I have good luck by gluing the cork gaskets into the tin covers(using the brown smelly gasket cement SILICONE doesn't work near as well) and using axle grease on the side which seals to the head... make sure to tap your cover rails back flat... any depression around the bolts will not allow the cover to pull up evenly and this allows the cover to weep.

[Joe L.]

Re: 427/435 Valve Cover Gaskets

I will now be on my 3rd set of valve cover gaskets. I am using the Fel-Pro black rubber type and they always seem to split over time at the bolt holes. If I don’t tighten them down pretty good they leak. If I do tighten them down really well they seem to split over a few months. They end up blowing out and oil spills everywhere. The car is very original and came with rubber gaskets installed. These do not have the bolt stops and steel reinforcements. Should I buy better rubber gaskets or go with cork, which I assume was original to the motor. Suggestions?

Charles-------


The best gaskets for small blocks and big blocks are Fel-Pro Cork Lam. These are a "rubberized cork" with a steel core. For a big block the Fel Pro part number is 1630. Never over-torque the bolts. If valve covers in area of the bolt holes are distorted, then they need to be straightened.

Original gaskets were cork with an "aluminum" coating. GM #3860315. Now discontinued.