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Discussion Starter #23
After everything Zray just said?
I take his opinion into consideration. I also have to take everyone else’s opinion in this thread into consideration. I also have to consider Ford’s engineers and how they felt to properly seal the manifold. I also have to consider what if my manifolds aren’t completely straight. Sure, I could machine them (which costs more money), or I could use a <$20 gasket. It’s not that I ignored him, it’s that there are lots of factors at play.
 

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I only like doing a job one time, correctly as for me my prof race engine builder told me, "no gaskets needed" while he was rebuilding it.
Consider a few yrs from now if/when gaskets get blown out, the aggravation of reaching into engine bay a 2nd time to repair.
 

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I’m definitely using a gasket. Still trying to comprehend the differences in the two though.
Differences in the two:

Steel shim gasket: Used in OE application where manifold sealing surface is flat.
Composition gasket: Used when manifold sealing surface is NOT flat.

Note: Manifold sealing surface was flat when motor was new and using the composition gasket because it isn't is a Band-Aid to fixing it right, IMHO. Sort of like using RTV in place of lifter valley end seals.... but that's just me.
 

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"........ Note: Manifold sealing surface was flat when motor was new and using the composition gasket because it isn't is a Band-Aid to fixing it right, IMHO. Sort of like using RTV in place of lifter valley end seals.... but that's just me.
^^^^^^^ +1

OP, bandaids are not an acceptable repair. A bandaid fix is always going to be a temporary, but maybe by the time it fails you will have sold the car and it will be someone else's problem.

If you wanting to use a composition gasket because your manifold and / or heads might not be flat, then have a machine shop do the right thing and resurface the parts properly. Then after the parts are flat, you can use the steel shim gasket, or no gasket, whatever you prefer. Either way, the possibility of a future leak will be infinitesimal vs. using the composition gaskets.

The machine shop cost will not be much more than the cost of a quality composition exhaust manifold gasket set.

I'm done. Everyone, including me, can now breathe easier.

Z
 

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Acooltj, the factory didn't use a normal gasket here for the reason of heat transfer. the exhaust manifolds get extremely hot, and if they are bolted directly to the head, or if you use a solid metal 'gasket' ( what you're calling a heat shield ), the water jackets in the head can suck up some of the heat. If you run a gasket that acts as a barrier to heat transfer, the manifolds will be too hot and they will loose the seal, they may also warp and crack. If you think that your heads or manifolds aren't smooth enough, have them surfaced. If you can't get them surfaced, and you think you must have a gasket to help seal surface irregularities, get a solid copper gasket from Hussey or Mr gasket. The copper is soft enough to seal it up, and will still allow good heat transfer. 35 yrs machine shop experience. And remember, Ford used nothing or just a solid metal shim. Think hard on this. LSG
 

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Discussion Starter #29
When I said I’m definitely using a gasket, I meant the heat shield/shim as OEM intended. I just wanted to make sure which part was the correct one. Thank again to Bart for clearing that up. The 95000 is the winner and it will be same as Ford intended it.
 

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Took the exhaust manifolds off my 410 today and there was no gasket. There’s a thin piece of sheet metal that I would call more of a heat shield than a gasket, but that was it. Is this normal? Should I go back with a gasket even though it didn’t have them originally? Below is a pic of the heat shield.
View attachment 738759
You are correct, that's a heat shield, protecting the spark plug boots. Exhaust manifolds typically had no gasket from the factory. I'm not aware of any Ford (or Chevy, for that matter) that had a gasket from the factory.
 

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Discussion Starter #31
You are correct, that's a heat shield, protecting the spark plug boots. Exhaust manifolds typically had no gasket from the factory. I'm not aware of any Ford (or Chevy, for that matter) that had a gasket from the factory.
And that’s what I wanna go back with. My thinking is that if it has lasted these 50+ years from the factory, then it’s good enough for me.
 

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"these" didn't last 50+ years. They were installed sometime between assembly line and the time you bought the car. 22GT's point was: when it rolled off the line, it didn't have gaskets or heat shields. Ford didn't waste any money on unnecessary parts on mass-production cars, and when Mustang hit the market it was all about mass-production.
I'm looking at a lot of advice here on going "no gaskets". There are lots of people with a lot more experience and knowledge than me. I've followed their advice (on this forum and the late, great CMF forum) since 2004.
I'm checking the box for "No Gaskets".
Do it once. Do it right... and machine them if you have to. You'll be happy you did. (I didn't have to... just sayin').
 

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While I agree with no gasket with iron heads/iron manifolds, I'm not sure I'd wanna pull the heads of my FE to check for "smoothness". When the engines out and getting disassembled, for sure. Till then, I'd take LSG's suggestion of a copper gasket.
 

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Discussion Starter #34
"these" didn't last 50+ years. They were installed sometime between assembly line and the time you bought the car. 22GT's point was: when it rolled off the line, it didn't have gaskets or heat shields. Ford didn't waste any money on unnecessary parts on mass-production cars, and when Mustang hit the market it was all about mass-production.
I'm looking at a lot of advice here on going "no gaskets". There are lots of people with a lot more experience and knowledge than me. I've followed their advice (on this forum and the late, great CMF forum) since 2004.
I'm checking the box for "No Gaskets".
Do it once. Do it right... and machine them if you have to. You'll be happy you did. (I didn't have to... just sayin').
My grandpa bought this car brand new (1966 Mercury Monterey) in 66 and it’s all original, completely unmolested. 52,000 original miles. It sat in storage for 25 years.
 

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Ford dealers have been known to install the heat shields, as well as many other items that people often perceive as being “factory”.


I doubt anyone knows the entire service history of any car, regardless of how long it’s been in the family

.just saying.

Z
 

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Frank, the metal 'heat shield' is a factory install. Its to protect the plug boots, as stated. It is not a 'gasket' as we normally think of them. Our man could help the sealing, if he is worried, and the heat transfer, with some copper spray paint before assembly. LSG
 

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Since I just replaced the heat shield gasket on a '73 390 recently I'll offer a little information. The "choke stove" is located between the #3 and #4 exhaust ports. The stove is a hollow cavity that is supposedly filled with wire mesh. There is a square metal plate that covers the cavity on the engine side of the manifold. The cover plate is held to the manifold with a single, large head machine screw (I'm guessing it's at least a 1/4" screw and possibly a 5/16") with a slot for a blade screwdriver. The head of this screw is "proud" of the actual ports. In order to machine the manifold flat this screw will have to be removed. I can imagine what a PITA that will be with 40-50 years of heat cycles leading to rusted threads.
The new FelPro heat shields are marked LEFT and RIGHT. The right side has a tab with a half circle cutout that fits around the tube from the choke stove to the carb. So they serve some purpose other than simply protecting the spark plug boots.
 

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Discussion Starter #38
Since I just replaced the heat shield gasket on a '73 390 recently I'll offer a little information. The "choke stove" is located between the #3 and #4 exhaust ports. The stove is a hollow cavity that is supposedly filled with wire mesh. There is a square metal plate that covers the cavity on the engine side of the manifold. The cover plate is held to the manifold with a single, large head machine screw (I'm guessing it's at least a 1/4" screw and possibly a 5/16") with a slot for a blade screwdriver. The head of this screw is "proud" of the actual ports. In order to machine the manifold flat this screw will have to be removed. I can imagine what a PITA that will be with 40-50 years of heat cycles leading to rusted threads.
The new FelPro heat shields are marked LEFT and RIGHT. The right side has a tab with a half circle cutout that fits around the tube from the choke stove to the carb. So they serve some purpose other than simply protecting the spark plug boots.
I did notice that screw and plate but was unaware what it was for.
 
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