Original valve covers were leaking, ordered new Mr. Gasket covers for the 302, JEGS cork gaskets. Some of the old timer threads seemed to like the cork gaskets better. I tightened in sequence to spec (3-5ft-lbs) As soon as I started it, let it run, it was dripping onto the header. Are the cork junk, go for Fel Pro?

 

If they've been overtightened in the past, they're probably distorted by now near each screw/bolt hole. The sealing surface should be FLAT, and the area surrounding each hole should NOT be depressed (looking from the top side).

A ball peen hammer can be used to restore the original flatness.

 

What works is to seal the gasket to the (flat) valve covers. Coat the side mating with the heads with clean oil and let it soak for a while, then install.

 

This is what I do; I "glue" the gaskets to the valve covers with Permatex No. 2 or High Tack; no sealant whatsoever on the head, makes it easy to remove & reinstall them later for whatever reasons.

 

I used the Felpro rubber gaskets. Install them hand tight with a socket and extension and that's it. Just adhere them to the valve covers with contact cement. Never a leak. After a drive or two they get stuck to the head. Very hard to remove. Never liked cork.

 

I think he said he bought new aftermarket valve covers if I read it correctly.

If they are chrome, I have heard of people having problems with the gaskets scooting around on the chrome surface. The glue idea may work to combat that. Usually the factory covers also have a lip with cut-outs along the edge. The new gaskets are supposed to have tabs that fit into these cutouts and keep the gasket in place.

Also, I do not like some of the cheap chrome valve covers. They do not have very good oil baffles where the PCV valve and the other pipe plug into the cover. Maybe they have wised up and improved them, but compare them to the factory cover. The factory has very good oil baffles that keep the PCV valve from sucking oil down into the engine. Been there, done that.

Some aftermarket stuff is good quality and is a improvement over the factory stuff, some of it is not and can cause problems.

 

I returned them to JEGS along with cork gaskets, hopefully they'll refund.
Lady indicated they should, I advised her I followed all instructions.

Anyway, cleaned up and painted the stock covers, Fel-Pro blue silicone gaskets, no leaks.

Later on, after I upgrade the heads to GT40, I'll go with something really nice and high quality. Thanks for all the replies and feedback.