Exhaust manifold gasket help please.

-

Arron tate

T B L
Joined
Sep 12, 2018
Messages
494
Reaction score
448
Location
USA
Hello fellow FABO members.
Question,
Does anyone have a suggestion for a better fitting gasket for my exhaust manifolds.
As noted in the pix the bottom has very little contact area thus it leaks.
The only number on this ill fitting gasket is B90460
I flipped the gasket over so you can see the contact area between the manifold and the head.
The gasket does align correctly with the bolt / stud holes.
Correct / better fitting manufacture and part number would be of great help.
Happy Mopar :)
Thanks in advance
Arron.

Exhaust Manifold gasket 1.jpg
 
I tossed the gaskets on my power wagon 20 years ago,a skim of high temp silicone and its been that way since.
After pulling manifolds on different vehicles and there were no gaskes, i figured why not.
 
I tossed the gaskets on my power wagon 20 years ago,a skim of high temp silicone and its been that way since. After pulling manifolds on different vehicles and there were no gaskes, i figured why not.

Hello Tooljunkie,

Yes I agree as we do the same with our tour type modified sealing the pro fab tri Y headers to the LS2 RYR heads.
They claim that the gasket does in fact change the flow of the head and recommend just using Loctite 59630 Superflex red sealent.
That said on this application I am trying to correct what someone else used when they installed the manifolds.
I figured that my fellow FABO members would be able to steer me down the correct path on using the right gasket as we are keeping with the OEM style on this restore.
As always the FABO members were able to provide me with the info needed to get the right gasket the first time.
Thanks to all FABO members for all your continuing support.
Happy Mopar :)
Arron
 
I tossed the gaskets on my power wagon 20 years ago,a skim of high temp silicone and its been that way since.
After pulling manifolds on different vehicles and there were no gaskes, i figured why not.
Same here, the factory never used them.
 
Same here, the factory never used them.

Hello 69hemibeep,
Are you saying that from the factory Plymouth / Dodge did not use gaskets on the LA engines?
If so did they use a sealant ?
Happy Mopar :)
Arron
 
I was surprised when I first read this too. I've always used them though.
Hello 69hemibeep,
Are you saying that from the factory Plymouth / Dodge did not use gaskets on the LA engines?
If so did they use a sealant ?
Happy Mopar :)
Arron
 
I was surprised when I first read this too. I've always used them though.
Hello 4spdragtop,

You were surprised when you read it "Here" on this thread "Or" some where else?
Is it true confirmed fact or urban legend?
I am new to Mopar so I am trying to copy how the factory would have assembled the manifold to the head.
Thanks in advance for all the help on this topic.
Happy Mopar :)
Arron
 
When everything is machined dead flat from the factory it would only make sense to not use gaskets.....but everyone knows that cast iron ages and with years of heat cycles the cast iron is no longer dead flat unless you get the manifold mating surface re-machined as many folks do. So, if your manifolds are still "dead flat" (machinist term) then you should be OK, if not I would use gaskets. I've always used gaskets myself because it doesn't make things any worse but it can seal up some warpage caused by all the decades of heat cycles. treblig
 
in the 1960s and 1970s mopar did not use a gasket. and they used very thick iron manifolds, and I have found that good used manifolds are straight enough that a light sanding with a block and fine paper is good to go. now maybe if old manifolds were overheated and or loose-maybe not so good until remachined
 
in the 1960s and 1970s mopar did not use a gasket. and they used very thick iron manifolds, and I have found that good used manifolds are straight enough that a light sanding with a block and fine paper is good to go. now maybe if old manifolds were overheated and or loose-maybe not so good until remachined

Thanks to all that helped.
This is why the FABO site is worth its weight in gold (duster that is lol).
Happy Mopar :)
Arron.
 
I use a thin layer of high temp RTV is all. Same with a good set of headers. I got tired of gaskets blowing out every 1500 miles.
 
I NEVER use any sort of gaskets on cast iron manifolds..Slant Sixes being the exception.
Just bolt them straight to the head and be done with it.
 
as on as many nuts and bolts as possible - retorque. thick exhaust manifolds do not need a gasket, a thin layer of hi temp silicone - left to cure overnight is good. on my Hooker headers I used silicone on the header and mr gasket ultra seal gaskets. retorqued a few times - all good 20 years and counting
 
Depending on the 'flatness" of the exhaust manifold mating surface running no gasket may not be an option??? Most of these manifolds are over 40 years old, thousands of heat cycles. The chances of the mating surfaces being flat is minimal. treblig
 
Last edited:
-
Back
Top