Anyone know a quick cross reference for the donut style gaskets for Tom's header to the exhaust pipe?

I havent been able to seal mine completely since I got them and I figured out why a couple days ago. The monkey who made my exhaust threw the donuts away! I never realized they were needed and thought something else was wrong.

So.... anyone know what kind of car or truck's gasket I can get from a parts store to put in there? I spent about 15 minutes behind the counter at Autozone digging through their gasket bins to not quite find what I was sure would work. A lot that might have but nothing quite like the pictures on Langdon's website.

I'd like to find something locally so I can fix this on Saturday. It's going to be 60 and sunny, all the salt was washed away, and my wife will be back from a week away for work.

Bump just so this is on the landing screen. I'd really like to fix this tomorrow morning...

You should call Tom directly I am sure he will have the answer.

Shot him an email. I'll wait.

you should call

He's closed until the 29th....

darn. It seems to me you should be able to take one of the headers to a muffler ship and match it up to a head pipe that fits. The donut goes with the head pipe size. I cannot imagine that he used something strange. If the headers are set up for a two inch headpipe flange, you use the donut for that flange.

It's a 2.75" but if you look at his website they're not like others. His are double-beveled.

Which motor? the later chevy is 2.25 and the early chevy is 2. Uses regular exhaust donuts as far as I can tell from the photos

250.

The Langdon headers are 2.75" each.

http://www.langdonsstovebolt.com/store/#!/Stovebolt-Cast-Exhaust-Headers-for-GM194-230-250-292-engines/p/1395980/category=412417

Are you positive about the size? It looks like his headers for the 250 use a 2.25 head pipe unless you have something different?

Nope. It says factory, Offy and Clifford use 2.25" pipe. His are 2.75"

I'm really confused by this. First, Offenhauser doesn't make a headers or exhaust manifolds for the Chevy inline six. Secondly, the Langdon Stovebolt exhaust manifolds/headers are a dual 2.75" outlets? That's huggggge!!!!! The original stock exhaust was a single 2", while my later stock integrated exhaust is 2.25", and 292 HD exhaust manifold is 2.5" which is plenty big for single street exhaust. Dual street exhaust should be 2" pipes. So if you got Stovebolt manifolds you have to start with dual 2.75" header pipes and then reduce those down to dual 2" pipes?

I swear they are.

The bolt holes on the flanges are 4" apart. Tom, himself, told me 2.75".

My exhaust is reduced to 2.5" right at the flange. Exhaust guy welded 2.5" pipe to the 2.75" flange. From there the pipes go down and Y into a single 2.5" exhaust pipe back to a Flowmaster 44, over the axel and dumps behind the rear wheel.

It tends to drone a bit. Hopefully when I swap transmissions I'll get out of the high RPM's on the highway and have a quieter ride.

I ordered a pair of 2.5" 2-bolt flanges from Jegs that look to be pretty thick. I'm hoping I can crank them down and get a good seal.if the bolt holes dont fit I'll trim them I to slots so they do.

Tom is the man, so.....wow. When I got to do my non-integrated head swap, depending on how much in funds at the time, I may go with the 292 HD 2.5" and make a 2.5" header pipe to follow the stock 2.25" one. Or I may splurge for Langdon Stovebolt manifolds/headers. I have a '77-'81 Z28 cat back resonator setup, which have 2" inlets on the resonators. So I can just take dual 2" pipes back to the Z28 resonators. So I don't know if having a reducer on the headers from 2.75" down to 2" is too restrictive, and I should use multiple reducers to step it down until it reaches 2"? I also would have a crossover at some point, but maybe that can be worked into the reducers somehow with an X pipe.

I think you have this wrong. The cast iron headers he sells for the 230, 250, 292 Chevy fit all intake manifolds, factory, offy, clifford, and his website specifically says they use a 2.25 head pipe. 2.75 is really big. Something is amiss here. If his website info is correct, a 2.50 head pipe is too big and the donuts for a 2.5 will not work. It just seems more likely that what you need is the 2.25 head pipe and the accompanying donuts.

I have his in stock. Here are measurements from the real thing. The donuts have a metal area that slides into the manifold.

So it is a 2.25 head pipe with the appropriate donut for a 2.25 head pipe flange? Or is it larger 2.75 head pipe and flange.

It's definitely 2.75"

Spoke with Tom Lowe: It's 2.25". I was mistaken.

I think this will work: http://www.shop.com/Walker+Exhst+31668+E...EtDSRoCtf_w_wcB

Thoughts?

That looks to be the correct one.

I had a feeling. 2.75 would have been really large for the application. Glad you got it sorted out!

Just found 2 on Fleabay for under $25 shipped. Should be in on Friday.

Hopefully this will help someone out in the future. It's a Walker 31668.


Thanks for your help, guys. Especially Tom. I can't wait to finally drive the darn thing without smelling like exhaust!

Hmmmm....given some thought on exhaust manifold. If I swap to the 292 HD 2.5" exhaust manifold I'm just replacing the 2.25" header pipe with a 2.5" version back to the cat-back Z28 exhaust. But if I'm a little richer at the time and go with the Langdon manifolds/headers with heat plate, maybe I should go with the 2.25" pipes to a 2.5" Y that runs back to the Z28's 2.5" to 2" Y-pipe. Since there's going to need to be a few twists and turns on the pipes coming off the Langdon Stovebolt manifolds/headers, the extra diameter on the bends may be better than 2" bends restricting it further. It would reduce the number of new feet of pipe and bends, plus eliminate the need of a crossover pipe.

Walker 31668 is NOT correct.

I'm using 2-hole gaskets for now until Langdon gets back from vacation. They're working OK but still slightly leaking.

Are you using just gaskets, donuts, or are you using both? You should be using both.

Just gaskets for now until Langdon gets back in town and I can order the right stuff.

So far the gaskets seem to be holding OK. At least I can drive it without smelling like I sat in the muffler.

I am going to be really surprised to find that you have to use a donut different then the donut for a 2.25 flange head pipe. It would not make sense because a larger donut would not fit a proper 2.25 headpipe. Will wait for the update.

The 2.25" donut was actually too big. Might be a weird size. Hopefully Langdon will be back soon and answer my email.

Langdon is back. Just called him. He has them and is going to send them my way. Sounds cheaper than the other donuts anyway.

As always Tom is great to deal with.