Good question. I hope we get a good answer.
Id like to know for sure

 

I've been using the Mr. Gasket Ultra-Seal gaskets for years. They have a steel core and work better than any others that I've tried. I've run the aluminum ones you reference and even solid copper with sealer. The Ultra-Seal lasts the longest. Of course you need to check the header bolts a couple times a year. And, my car is fuel injected.

 

Hows fuel injected work into the mix ?

 

Oh yeah ok.
I'm gonna order some of them gaskets before I forget and the thread gets lost in the closet.
They've all leaked on me too soon . Just a real arse ache changin em

 

These right ?

Amazon.com: Mr. Gasket 5907 Ultra-Seal Exhaust Manifold Gaskets - 2 Per Set : Automotive

Buy Mr. Gasket 5907 Ultra-Seal Exhaust Manifold Gaskets - 2 Per Set: Exhaust Manifold - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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Correct brand, but you need to make sure they are the right size for your headers.

 

I've got headman 1-5/8 for my sb

 

I've never had any leaks with Fel Pro header gaskets on the carbureted engines I've had, but on the fuel injected blown engine I had back in 2006 in a street/strip car, I used Percy's "dead soft" aluminum header gaskets when I installed a pair of stainless steel Kooks headers, and after some drag strip use, and 44,000 miles, those gaskets never leaked either, right up to the day I sold the car. I might try these Remflex gaskets on my current build. They used to offer to send you a silver dollar sized sample of their header gasket material, so that you can see how different it is from other header gaskets.

The Remflex gaskets are thicker than others, and are very soft, and the material bounces back or rebounds after you squeeze it, or dig your fingernail into it. It retains it's former shape after you let go and take the pressure off of it. So the manufacture's claim is that these gaskets will follow the contour and shape of the head and header flange surfaces as they heat and cool/ expand/contract. I've never tried them though.

Remflex Exhaust Header / Manifold Gaskets

Another thing is that if you have heads that have rectangular shaped exhaust ports, and your header flange opening are round and/or the header gasket has round holes, then you might get a little bit of a mismatch which can invite leaks.

 

I make my own every time now and since I've been doing so, no leaks, no loose bolts.
This is Felpro material and cut with snips. It has an aluminum core.
If your header flange is thin and not flat, well no guarantees there.

 

I will second the Mr Gasket Ultra Seals that Steve mentioned. Have never had an issue with them. But like somebody else mentioned if you header flanges are not fairly straight then it will be hard to get anything to seal up.

 

X3 on the Mr Gasket Ultra Seals and flat surfaces

 

X2 on the Percy's

 

i always double up on mine and also the collector gaskets , a friend of mine used to soak his in water , old school trick

 

I find that the real problem with header sealing is the header flanges. Thin and what looks like hand ground with a belly buster on most "low cost headers" and some high buck headers also. I can't remember what gaskets are on my car, been too long since I changed them but probably Mr. Gaskets.

rotin

 

i'll agree with that.i swear they hire monkeys to grind those flanges flat.

 

I understand that copper is the best material for header gaskets.

 

The key to leak-free header gaskets is to retorque those SOBs as many times as it takes until the gasket takes a permanent set. I hit them at least a 1/2 dozen times and I “get a little more” on them every time.
I prefer the cheap white ones as they come off easy and don’t brinnel the alum heads

 

This--^
On the advice of someone here, I did the same and haven't had any problems since. Get the engine fully hot and let it fully cool, then re-torque every bolt. Repeat until they no longer move. I also did this about a 1/2 dozen times after installation and (each time) before I hopped in it for a drive. Using paper with some high temp RTV.

 

Match your head port and header ports to exhaust gasket. I talking BB round ports or D ports. Most BB
Headers are round ports. Mix them up and the dreaded exhaust leak pops up. Tell tale sign carbon at headers edge to head seal. I think I used the FelPro performance exhaust gaskets.

 

Match your head port and header ports to exhaust gasket. I talking BB round ports or D ports. Most BB
Headers are round ports. Mix them up and the dreaded exhaust leak pops up. Tell tale sign carbon at headers edge to head seal. I think I used the FelPro performance exhaust gaskets.

This has always been an issue for me as almost all exhaust ports are "D" shaped, and almost all headers are round.

 

I use the remflex gaskets on everything: bbc, sbc, Landcruiser 6 cylinders. Never had one leak and never had to retorque one.

 

I've always had the best luck just using Felpro exhaust manifold gaskets. One side flat, the other side is made to collapse when the bolts are tightened down. I've never had one leak on me. I prefer the one's that aren't one long gasket, as I like not seeing the stupid gasket running along side the header flange, and causing clearance issues with the temp sending unit, etc.

 

I did re-torque several times.
My leaks are tiny, barely visible black traces, but apparently still enough to cause issues.
I am going to look deeper into some of the suggestions.
Never heard of most of these before now, thanks for the responses.

 

Check out SCE copper header gaskets

 

I also prefer Remflex gaskets. Just a heads up if you do get them, DO NOT bend them or they will get damaged and leak. I found out the hard way when I took it out the package trying to make it straight but it fell apart in my hands lol. I also use Stage 8 header bolts that way they don't get loose.

 

Looks like I am going to give the Remflex 2016 a try.
I am a bit impressed that they supply so many gaskets for heavy duty industrial use.
Operators of big equipment have zero tolerance for failed parts, it is just too expensive to have those machines inoperable.
So if they can keep that market happy our mere cars should be a cinch.
I will report back on them.

 

I've been using the GM 12617944 multi layer. Never had any sign of a leak.

Amazon.com: GM Performance Parts 12617944 Exhaust Manifold Gasket Set : Automotive

Buy GM Performance Parts 12617944 Exhaust Manifold Gasket Set: Exhaust Manifold - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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stokerboats is correct on my account. been using the sce coppers on my hedmans for over a year and no leaks. i did have to retorque two or three times the first month or so, but that was a small price to pay to FINALLY have no leaks. here is a link to their 2022 catalog: https://www.scegaskets.com/wp-content/uploads/2021/12/SCE-Catalog-2022-V2__WEB.pdf good luck, James

 

You guys can laugh if you want, but all I use is copper sealant. I don’t get leaks, even with square exhaust ports and round header tubes on my big block. Every header gasket I ever bought failed eventually, even Remflex. I sold those at my store when they first came out, was a real believer in them.

Devin