Correct valve cover gasket

[Dave C.]

I have a 66 BB which I am restoring. Were the original valve cover gaskets on the 427/435 cork or rubber? Which is better?

[Stephen L.]

Re: Correct valve cover gasket

The original gasket was cork..... with the tabs on. If the covers are painted then the gaskets (tabs) will have paint on them as they were installed before the engine was painted.
Its a matter of opinion as to which is better.... rubber is typically more durable.

[Joe L.]

Re: Correct valve cover gasket

Dave-----

Also, the original cork gaskets had a dull silver coating which, depending upon how much of the exposed gasket got covered with engine paint, may or may not have been easily discerned.

I don't like the original cork-type gaskets, at all (although I DO like cork, in general). The best for sealing, in my opinion, are Fel-Pro Cork-Lam with steel core (#1630) and Earle's.

[Dave Suesz]

Cork, no question...

For over 20 years I drove a mechanical cam, so pulling the covers was a 3-4 times a years operation. I had the original stapled steel covers, and the cork was compliant enough to provide a good seal, which the rubber ones would not do. With sealant on the valve cover side only, the cork ones can last a couple of years even with heavy use.

[Jack H.]

Re: Cork, no question...

There are several variation of rubber based gasket technology out now... If you're not concerned with factory concours originality and you have solid lifters to 'dink' with periodically, take a look-see at Fel Pro's PermaDryPlus line of rubber gaskets....

They're more expensive than cork (reinforced or un-reinforced), but they have several advantages including:

(1) They're reusable....
(2) They're a precision fit (no chemical sealants required).
(3) Built-in hole locks to thwart oil migration via valve cover fastening bolts.
(4) Built-in torque limiters--impossible to over-torque/warp the valve covers.

Check out Fel Pro's neat Form No. 263-98 (or later) gasket description phamphlet at your local distributor or check their web site (www.fel-pro.com) and read between the obvious ad claims for nice primer course in gasket-tiering.