SAAC Forum

The Cars => 1966 Shelby GT350/GT350H => Topic started by: 6s1640 on May 28, 2026, 02:56:34 PM

Title: Header Gasket
Post by: 6s1640 on May 28, 2026, 02:56:34 PM
Hi all,

I have two questions relating to the header gaskets for the tri-Y headers.

1) Who was the original supplier for the gasket?
2) Any recommendations on a gasket that looks closest to OEM?

Below is a screenshot of what the Internet says, Cyclone sourced the gasket from "Best Gasket".  Is this accurate?

Thanks

Cory
Title: Re: Header Gasket
Post by: 6s1640 on May 29, 2026, 02:56:36 PM
A fellow member sent me the judging sheet for 66GT350.  The rule says to check for "white" header gasket.
Title: Re: Header Gasket
Post by: Bob Gaines on May 29, 2026, 03:15:06 PM
Quote from: 6s1640 on May 29, 2026, 02:56:36 PMA fellow member sent me the judging sheet for 66GT350.  The rule says to check for "white" header gasket.
That is because they were historically typically white.
Title: Re: Header Gasket
Post by: J_Speegle on May 29, 2026, 03:36:08 PM
Quote from: 6s1640 on May 28, 2026, 02:56:34 PMHi all,

I have two questions relating to the header gaskets for the tri-Y headers.

1) Who was the original supplier for the gasket?
2) Any recommendations on a gasket that looks closest to OEM?

Below is a screenshot of what the Internet says, Cyclone sourced the gasket from "Best Gasket".  Is this accurate?

Thanks

Cory

Never heard of "Best Gasket" but then again the "source" is AI so who knows where that came from. Lots of bad/incorrect info out there being found by people now using AI for their "research". Results is going to be interesting, guessing it will be like those restorations that rely on the Assembly Manuals only as we've seen in the past.  ::)

Don't know of a specific brand to point you to currently. Too many companies shutting down or being bought by other companies. I rely on simply, though takes time, a visual inspection of the shape and make up of what is available at the time and if I need to paint (if you can still get white header paint)  them then so be it to get the end result needed.  Also if you find the correct shaped ones I suggest you purchase a few sets either for later or to help out someone else in the future. Good luck  in your search
Title: Re: Header Gasket
Post by: pbf777 on May 29, 2026, 03:53:21 PM
Quote from: J_Speegle on May 29, 2026, 03:36:08 PMNever heard of "Best Gasket"

    See: https://bestgasket.com/about-us/

    Scott.
Title: Re: Header Gasket
Post by: 6s1640 on May 29, 2026, 04:15:43 PM
Hi Scott,

I did try the Best Gasket website and searched for the header gasket. It came up "go fish". Thank you for the link.

Hi Jeff

I agree with you.  I am a little skeptical of the Internet search, but it did get Cyclone right.  It's possible to purchase white header gasket material and custom cut them. My son has a laser cutter that could do the job. All I need is an image of what an original gasket looks like and reverse engineer it and make a period as close correct gasket. Mark Hovander told me they put original gaskets on either 003 or 002. What would be interesting would be if we can come up with an image and see what we can do from there.  I'll have to check the period catalogs to see if there's an image of that gasket for guidance.

Thanks

Cory
Title: Re: Header Gasket
Post by: 6s1640 on May 29, 2026, 04:28:52 PM
Here's an image from early catalogue showing the Tri-Y headers with gaskets. The gaskets appear to be different than White, however, a white gasket probably wouldn't photograph very well. They may have altered the gasket so they could photograph it. I'm mostly looking at the shape.
Title: Re: Header Gasket
Post by: 6s1640 on May 29, 2026, 04:31:57 PM
This is the closest aftermarket gasket I can find that is white, but differ slightly in the shape.  They are made by Mr. Gasket No. 253.  Not all of the gaskets are white on one side. Many have printing on both sides. But I found a seller that at least in his image show White on the one side in the attached image. We'll see if they show up White on the one side or not. I bought a couple.
Title: Re: Header Gasket
Post by: Bob Gaines on May 29, 2026, 04:34:17 PM
Quote from: 6s1640 on May 29, 2026, 04:28:52 PMHere's an image from early catalogue showing the Tri-Y headers with gaskets. The gaskets appear to be different than White, however, a white gasket probably wouldn't photograph very well. They may have altered the gasket so they could photograph it. I'm mostly looking at the shape.
That is the classic shape. There was a dark gray material too but white was more typical from all that I have seen and the general consensus.
Title: Re: Header Gasket
Post by: KR500 on May 29, 2026, 07:14:27 PM
Ask Scott Fuller he maybe able to help. A few years ago (3-4?) got a complete 66 GT350 system and he supplied white gaskets at that time. They were from a name brand company, it could have been Mr.Gasket.