Rubber vs. Cork Gasket
 

My pushrod cover gasket has developed a pretty good leak. At first I thought hey, free rust prevention for the block and transmission :D but now its to the point where I'm losing a quart every couple hundred miles. I see that Rock Auto offers two types: an "old style" rubber gasket and an "updated style" cork gasket.

Anyone have any opinions on which to choose? They're like $5 difference so money is not an issue. Also, I have a fairly good idea of how to go about changing the gasket but any tips or tricks would be appreciated.

Thanks guys.

I prefer the cork style. They seal better for me. After a while the rubber ones seem to get hard. But the cork ones will not endure several removals and re-installs.
I like to clean the surfaces of head and cover and then smear a very thin film of adhesive sealant on the head to keep it in place. Re torque after use but do not over torque.
Be sure the sealing surface is flat around the bolt holes by inverting the cover and tapping the metal flat while holding the cover on a long socket or piece of tubing held snug against each hole.

Biggest thing I have learned on gaskets is to let the gasket sealer fully set before installation no matter how flat and nice the two surfaces are to be gasketed. Otherwise the gasket can roll or shift during installation and you have to do the whole thing over. Seems to promote a leak-free installation like that.

Thanks FTF and Dave. I guess I'll go with cork then, I only want to do the job once anyhow. I'll pick up some adhesive sealant and follow Dave's advice to let it fully set before re-installation. Thanks guys.

I personally like the Fel-Pro rubber gaskets. I did mine about a year ago. Used some adhesive to hold it in place, let it cure, then installed. The hardest part was getting the bolts started. Had to use a box wrench to turn and a socket extension to mash the bolts to get some threads started. Was a two person job.


https://cimg3.ibsrv.net/gimg/www.for...e7eccdc737.jpg
Before Original pushrod gaskets. Leaky.
https://cimg6.ibsrv.net/gimg/www.for...d7d1704cbd.jpg
After

A cork rubber hybrid gives the beat of both world's without the draw backs.

Just a follow up: got the cork from Rock Auto since it was apparently a "new and improved design". Stuck it in with a little bit of adhesive. Got the bolts tightened down, and the leak is gone!

For the record my back bolt on the cover was so loose I'm surprised it didn't rattle out!!! Why it was like that I'll never know. It was definitely a job threading that cover in behind the PS/AC compressor bracket.

Cork compresses over time and does not recover. This then makes the bolts loose. Rubber ones don't do this but can deform, harden and weep. Cork seals very well a lot of new gaskets are cork/rubber hybrids so you get the benefits of both and none of the cons.