68 GT 500 exhaust Manifold gaskets needed!!

[daltondavid]

Not having much luck so I am turning here to see if anyone can help. I have an early 68 GT 500 428 and I need exhaust manifold gaskets. someone had put header gaskets on there and they blew out. I was curious why someone would put Header gaskets on exhaust manifolds. Well now that I am trying to find the right gaskets, I am seeing why!! any help please e-mail or leave a reply.

[Mark IV]

I am not home today so I can't check my FoMoCo parts manuals but I am pretty sure they did not use gaskets! Many Fords had metal to metal on the heads to exhaust manifold. This is why it is important to have both head and manifolds surfaced when rebuilding. If they did use gaskets, they likely are a metal shim style that includes a heat shield for the plug wire and have a raised bead stamped in them that "crushes" to form a seal. if they are this type they are part numbers C1SF-9448-E and 9448-F...and don't ask me why I know those numbers by heart!

I will check tonight and post.

Rick

[daltondavid]

Rick, thanks for the info. A friend had suggested getting the manifolds milled and mounting without gaskets. This may be a viable option....

[Mark IV]

I assume with the number on your 500 it is NOt a KR?

I will let you know on the gaskets. If you need them, I may have a set kicking around. Also if you do not want to remove the heads for machine work, you could install a set of composite (not header) gaskets that come in most rebuild kits and are avaialble from NAPA as a stand alone. these typically have a waffle face aluminum side and a side that is gasket material.

Rick

[daltondavid]

yes it is an eary 500 non CJ. I got turned on to a company called SCE gaskets in California. www.scegaskets.com check out their web site. They make a Copper Header Gasket that looks real interesting. as well as Gaskets for many other applications.

[68gt500]

The original manifolds are mounted without gaskets.

To get a leak free installation ist is important to have the manifolds and head surfaced. Then install with a very light coat of high temp silicone - no more leaks.

I´ve been there.

Currently I´m running Hooker Super Comps, Edelbrock heads and the white MrGasket header gaskets - no problems either.

BTW: Mine is # 1410

[Mark IV]

..is correct. the manual confirms the 428 cars had NO gaskets, the CJs did use the metal gasket/shields I listed.

And use a VERY thin coating of the sealant, if you use a thick layer it will not work.

Rick

[daltondavid]

Originally posted by 68gt500


The original manifolds are mounted without gaskets.

To get a leak free installation ist is important to have the manifolds and head surfaced. Then install with a very light coat of high temp silicone - no more leaks.

I´ve been there.

Currently I´m running Hooker Super Comps, Edelbrock heads and the white MrGasket header gaskets - no problems either.

BTW: Mine is # 1410

Sounds like a nice combination. I appreciate the info. I really am torn about going Headers, Heads and intake, but I do not race the car. I cruise and pull some burnouts. But who knows what the future holds??

[A Snake]

If your car is now in original condition, it would be a real shame to start changing things.....even putting on headers. It's hard enough to find an original car, unless it has been through a thorough restoration.

Good grief! That 428 should stuff you back in the seat enough as it is.

Advice from an old timer......don't modify the car. It ruins both the value and the mystique of a fabulous car.

On your exhaust manifolds, I would suggest checking them with a straight edge and doing the same to the heads before I went and spent a bunch of money on machining.

Just in case you've never done this, you need an accurate (+or- .oo1") straight edge and no, the ruler out of a machinist's square is not good enough. It needs to be long enough to over hang on both ends of the manifold and heads.

You want what ever you're looking at in relative darkness, whether it is the head or a manifold. Next, use a shaded light behind the straight edge (away from you) so you see a "line of light" under the straight edge. DO NOT tip the gauge, stand it straight up so that the ground edge is flat on the surface you're checking. Now, a portable flourescent light is a good tool, because it won't shine in your eyes as you look.

If the gauge rocks, the surface is obviously is not flat. If you see the gauge showing light and dark along it's length, it is just uneven and light brighter in the center than the ends it is a hollow surface.

Next, use a feeler gauge along with the straight edge to determine just how far out of true the surface is. In my opinion, .002"-.003" is max and expect it to seal with the high temp sealant. More than that and one or both pieces need to be resurfaced.

Try the straight edge trick even before buying gaskets and make sure the surfaces are clean, bare metal before taking a reading.

Just some thoughts.

Al

[daltondavid]

my car is all original engine trans and rear with one rebuild on engine. The only mods I have done is DEmon Carb since original was not there and electronic ignition saving all parts of course! Originality is why the Exhaust Manifolds are going back in place. I also sent my Steering Box and all power steering components to Rodes Restoration in Galion Ohio. The guy sent my stuff back in three days. Awesome job everything looks and feels Brand new. I cannot wait to see how my Baby steers now! My box was Dry and loose! ANd he did all this with return Shipping for $505.00!! I considered the Flaming River route and not only was this cheaper, but It is still original.