Header to Down pipe sealing rings too thick

Hi all,
Connecting my exhaust today I found the sealing rings being supplied are too thick to allow me to fit my pipes into the headers far enough to expose the studs far enough. I tried crushing the rings with a hammer and also using some steel nuts on my flanges/studs but the brass nuts are barely able to get enough threads to make a good connection and I cannot fit a spring washer underneath them.

Anyone have this issue and solve it??

Many people have found the same problem, and it usually ends up that the old rings are still in there!

Years ago I was informed by the Terry’s sales guy that only the original factory sealing rings were any good. He rarely gave such advice (no doubt because so few real original parts could still be found), so I got the real Jaguar items - they fit just fine. Maybe you can’t get them anymore.
Of course I always got original when available, but he was very adamant regarding this particular part, when he wasn’t so quick and forceful about other items.

I just went through this process and, initially, thought that I had gotten the wrong seals.
The studs on my 68 just seemed too short.
I wound up getting a few threads started using steel nuts with no washers and then sequentially tightened them little by little. The seals compress fairly significantly. Once I had enough thread exposed I removed the steel nuts and added washers and brass nuts.
I did have to change out two studs on one manifold as the threads were corroded enough that they wouldn’t hold. The new studs are definitely longer.
Good luck,

Are you fitting new exhaust front pipes John? if so do you have recessed manifolds?
Peter B

I’m pretty sure the old ones are not in there, but I’ll double check that. Thanks

I searched and from what I saw the originals aren’t available any more.

I did the same using steel nuts to compress the seal but I’m still short of the threads I would like to see. New studs is another option I guess, but I’ll keep trying to compress them as you did.

not new parts just putting back what was there before. I do have the recessed manifolds.


I bought a set of gaskets on EBay that were thinner, and worked nicely (on Jeffs car… Need to buy another set for mine). These appear to be the ones I got from this seller:

Ray L.


Hi John, had a similar experience on the last install. My solution was to unscrew the studs as many turns as necessary to get the nuts started with just a thin plain washer. Once the gaskets had scrunched a bit I screwed the studs back in tight and switched out the plain washer for a Nord Lock set. I’m not sure if this new thing is because the gaskets are thicker or if the new studs on offer are a hair shorter on the fine side.

The gaskets compress a lot though so once that occurs it’s all fine.

That’s what mine look like - at least before I tried to compress them a bit.

Thanks for that Idea too. I’ll give that a try.

Fwiw, when I removed the downpipes on my car the donuts did not look at all like the ones pictured. They looked to me the same as the ones that were used on the older gm cars so I suspect someone substituted at some time. It might be worth your while to take your jag ones down to napa and see if they have something suitable. Big plus for gm ones is I do not remember ever having to retighten them. I hav3 not tried this myself but maybe it is a solution.


The ones I got were MUCH thinner than the stock parts - about half the thickness. We used them on Jeffs car, because one of his new exhaust manifolds didn’t have any recess milled into the flange for the gaskets. Yours CANNOT be that far off!

Ray L.

Maybe this cross reference helps?
P183A-230 Gasket Assortments, Illustrations & Interchanges.pdf (2.2 MB)

You’re correct! My old sealing rings were still on the ends of my down-pipes. In my defense, they had been corroded and colored to exactly match the color of the pipe junction at the top of the down-pipes so I never suspected this wasn’t just part of that junction piece. Dooooh!

Thanks to everyone that responded- I was very upset last night after spending hours messing with them. I’ve mutilated the replacements so new ones have to be ordered.


You are not alone. I had the same thing happen before I went to stainless steel downpipes. The original donuts were frozen so solidly to the downpipes I thought they were part of them.

Sounds like Jeff had the wrong manifold. The ones used on the XK140 (and probably the other XKs and period saloons) do not have a recess. I’ve seen several cases where an eBay seller has sold the earlier manifolds as being suitable for the E-Type, when they are not. The downpipes have a flange welded to the end of them:
…and a flat gasket is used:

1 Like

Yes David but I have posted this previouly.
The early version use of the sealing ring used a manifold that is not recessed
the manifold having just a chamfer for the ring to seat against. The down pipes
having a thin abutment for the holding flange instead of the later thicker item.
This method Ive seen mainly on early MK2s fitted with straight down manifolds, not the swept back variety, Might have been used on early E Types Perhaps a part number change 61 /62 to 63ish.
Peter B