Hi All
I’m having the age old problem of leaking valve covers on my 440, mainly, as per usual, on the passengers side rear. I have read various posts on the best way to remedy the problem but thought i would throw it out there to see what you guys have found as the best way to stop the leaking.
It seems there are the “no sealant” and the “use sealant groups”. The sealants that have been discussed are: Indian Head – Permatex Ultra Black, Right Stuff, Aviation #3, Super 300, Ultra Grey – Gasgacinch etc plus various types of gaskets, cork - rubber etc.
I have purchased brand new AMD pressed original style steel covers (not the ones they had trouble with) and thought now would be a good time to raise the topic yet again before installing them.

Any help would be appreciated
Thanks

I have not tried this yet on a steel valve cover, but it appears it's designed for that type of application. I was reading some customer comments on Summit awhile ago about cork oil pan gaskets being difficult to seal and a guy on there said this product is the way to do it. It never really fully cures so it maintains a degree of flexibility and doesn't crack or split. It's supposedly like a better version of the Indian Head stuff I think?

https://www.permatex.com/products/g...ermatex-form-a-gasket-no-2-sealant-3-oz/

The Right Stuff is so strong that it can be a real hassle to remove later.

RTV = honestly not a fan of that stuff anymore. I don't even own a tube of it.

What I've done for decades - and no leaks:
Make sure gasket rail (head and cover) are straight/clean/undamaged
Fel-Pro cork gaskets - with a bit of rubber content is fine - glued to covers with Permatex #2 (non-hardening)
Run it around the bolt holes, but no need to go nuts
Set gasket on/in cover rail, locate with bolts in the holes until it's tacked up
Light smear of wheel bearing grease on the surface that meets the head
Look the valvetrain over while it's all visible, make sure PCV & breather are clean & clear
Snug 'em on, run around in a circular pattern (inside out) a couple times

The cork will crush a bit, so I'll chase the pattern again a couple times over the next day or so
Done

I have never used the stamped steel valve covers on any of my mopars. Main reason they are thin and will bend/deform when you tighten the bolts down. Been using the cast aluminum "MT" valve covers forever and no leaks. The cast ones are strong and will even out the force from the bolts where the steel ones bend/warp. And i do not use tree bark for gaskets(cork) either. Just my opinion but cork is the worse gasket material ever.

Like topside said.

Plus - make sure the valve cover flanges do not have any bell mouthed bolt holes. Being new covers I doubt that is your problem but I would check them anyway.
Before assembling, I would place each cover on its respective head and see if they rock. If they do find out why.

I struggled a few years back getting a 4 bolt MaxWedge to seal up. In the end I found the cast flanges on both heads were not flat.

First time I had seen that.

i bought some of that to try Not EVER again . It was design to work for motorcycles and marine motors coolant passages, not for standard automotive application

I had the exact same leak at that corner. Do you have the normal stock stud there? I had that stud and when tightening the screw, it stopped at the shoulder of the stud where it did not cinch down the gasket. I put in another set of the valve cover set screws and the new stud shoulder was a bit lower. That cinched down the gasket and stopped my leak. Can't tell you how much frustration I had at that corner until I put in a different stud. Just something to look at.

You need flat rigid surfaces on both sides and a good gasket to prevent leaks. Trick Flow heads have a nice machined valve cover rail. A billet valve cover with a thick flange is super rigid and then use the Cometic gasket which is steel core covered with rubber. That combination never leaks and the gasket can be reused for years.

although i never really measured it, many, many, [and many more] years ago, i got the notion that the holes cast into factory iron heads were not perpendicular to the sealing surface, thus causing sealing issues using the factory tin valve covers.
not sure where i heard or read this information, or why it was done this way to begin with.
just throwing this out there for consideration.
if this is just conjecture or folklore, i don't know.
if someone knows for sure, or can debunk this as a myth, please chime in.

The blue Moroso gaskets. Not cheap, don't look "stock" but dammit, they don't leak !!

Depends on the head and the valve cover. The wrong combination of parts will rip the Moroso gaskets to shreds. The rubber peels right off if you use some cast valve covers with the Moroso gasket and cast iron heads.

That is true. The bolt holes are angled 5 or 6 degrees on cast iron heads. Aluminum heads are drilled and tapped straight. The factory cast iron heads did it that way so the head of the bolts would dig into the valve cover and create a "lock washer" effect.

Are these the ones you are using - Part Number: 710-93055? - I have a pair of these but they came with a disclaimer regarding using them with original style pressed covers and original heads. What combination of heads / valve covers do you have? Also do you run them dry?
Thanks for all the replies in this thread...a lot of good info.

Indy aluminum heads and Indy cast valve covers. Yes, dry.

mr. gasket 382, or cometic c5613-094 I what I use on that type of head/valve cover.

Agree with B1 Mr Gasket ultra seals. Mine have been on at least 15 years no leaks. Its all we run SB and BBs. Mine have been off a few times to adjust .Even with cheap Sumot valve covers they still seal.My kids 413 they were on 10 years same with his 360.No leaks

thanks for clearing this up for me Andy.
i guess i can still remember some things that are kind of strange.............

I need to clarify..... this was in response to the Indy head indy cover statement .

These will not work on a stock cover/ head application.

Exactly. There are gaskets that work great with aluminum heads and cast valve covers that won't work with cast iron heads and sheet metal valve covers. Sheet metal valve covers are almost impossible to seal, especially when mated to factory cast iron heads which do not have a smooth sealing surface.

Yep, I have a ripped up set of Morosos hanging in my shop to remind me to never spend $40 for these and try to use them with iron heads and/or stock valve covers. I have always used (before and after the Moroso debacle) Mr Gasket ultra seal gaskets glued to the valve cover with 3M trim adhesive. The yellow stuff that is like contact cement. I call it gorilla snot. No need to put anything on the head side. I also recommend cast valve covers no matter what gasket you use but a good set of stock covers is usable just more likely to resist sealing. Do not under any circumstance use anything like "Right Stuff" unless you're ok with using a BFH to get the covers back off. Do Not use Rtv sealants unless your ok with finding chunks of Rtv in your oil pickup screen.
By the way the gorilla snot also works good on oil pan and timing cover gaskets