Just swapped out valve covers and used the felpro hi temp gaskets. I used the orange permatex on the inside of the valve cover, let it dry and torqued them down correctly. But for some reason the passenger side will not seal and leaks oil out of the lower half right in the center onto my headers. both surfaces are clean and straight, what else can i do to try and get this to seal? Thanks

stock V/C's seem to only seal with the cork for me.

These are actually new chrome mopar valve covers because my stock ones didnt wanna seal either, but now these wont either....

I use cork..have found some valve covers will not seal even if you "weld them shut"....just kidding...on troublesome ones I use cork and install studs. This seats the cover exactly as it should be every time. ( 1/4 by 20)

Last resort is high temp silicone on valve cover side....then on head if needed....don't "overtighten"

Hmmm thats a really good idea using the studs, not to mention probably so much easier. Thanks alot man, any other input is still appreciated thanks.

I use cork gaskets and old fashion Indian Head sealer. They don't leak. Does stick the gasket to both surfaces so if you remove your covers often probably not a good deal. My cam is hydraulic with stock rocker arms so no reason to pop off the covers very often. Works for me.

another good trick is permatex the gasket to the valve cover then use white grease between the head and VC. that way you can remove them without destroying the gaskets and it seals really well. just my

you mentioned that you have headers.... is the flange interfering with the vc from going down all the way??

440, I had a 340 that did this once. Nothing worked. Finally figured out the holes were not stamped in the cover in the right location and so the cover was not siting on the head right. Swapped to one that was dead on and it never leaked with any gasket.
Tom

If you know the covers are straight, the bolt holes not drawn down,....the leak will occur generally between the head and gasket, not the cover and gasket,...while I prefere the Felpro orange silcone gaskets over cork,...either way, I just install the gaskets wit 3M HD spray adhesive,...if the gaskets are tabbed, I fit them to the covers, after I've applied a wet coat of spray adhesive to 1 side only, the side that contacts the head,....for tabless gaskets, I coat 1 side of the gasket with 3M HD spray glue, let it tack for a few moments, make sure the head is dry by wiping with acetone, them apply the gasket to the head,....the silcone orange premium gaskets will release without tearing, and the glue can be dissolved with acetone, and the gasket reused,...ex. valve adjustments/etc

Check to see if the valve covers are hitting the intake ports. Pretty common on heads that have been milled or some after market intakes. Might need a clearance notch near the top of the intake ports.

Try the blue gaskets with the steel core in them. Mancini's has them. Very good, no need for sealant. I have used them repeatedly with good results.

They cost more, but are reusable.

Had the same problem. Ended up using superformance gaskets from roadhazzard and still had to apply a thin layer of mopar gray rtv no more leaks. What ever you do dont get those blue moroso gaskets.