LMC catalog question

bugsiegel

Senior Member
I have developed and exhaust leak and I'm having trouble figuring out which exhaust gasket I need to order from LMC.
The leak is between the stock headers and where all three enter into one pipe.
LMC has an item called pipe gasket 40-4110 and exhaust pipe gasket 40-4391.
I have asked the nice girl on the phone but she as clueless as me.
Would the word exhaust imply the union between the engine block and the headers?
Thanks
 
Bugsiegel - I'm a bit confused. "Stock" and "Headers" are mutually exclusive terms for a flathead. In stock form, as far as I know, all flatheads had exhaust manifolds as opposed to headers. The fact that you mention 3 pipes coming into one leads me to suspect that you have someone's aftermarket headers on the truck. A picture would be a big help.
 
Looks like the 40-4110 is what you need .I'm looking at the LMC Fall Edition magazine ,page 38.It is a bit confusing .If not I would order both ,it's only $2.95 more.Just my opinion
:confused:
 
Sorry for the bad terminology I obviously using the wrong words in the wrong place.
Here's a photo of what I mean when I say three into one. You can see where the leak is as well.
While we're on the topic, what is the difference between headers and what I have as shown in the photo?
Is the photo shown, factory? Left bank
 

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The gasket between block and manifold and manifold and pipe are the same size. The cast iron manifold is stock headers are usually steel pipes welded together. Yours looks stock to me.
 
Is there a real flow benefit in having headers verse stock exhaust manifold?
I do have a stroked and bored engine. What I don't want is a louder truck, will headers increase sound? and the last question is I read in here someplace but don't remember exactly what I read but the further back your muffler is the louder or quieter the exhaust will be. Which is it?
 
Make sure your engine pipe is not hitting the oil pan, which won't let the pipe sit properly to the manifold, causing a leak. THere should be a 1/2 inch or so between pipe and pan. Just enough for the clamp to go around the 2 pipe pieces. You can get that gasket thru Napa or any good auto parts store.
 
If you are really going to fix this leak for the "long haul", i would suggest you pull the exhaust manifold and the exhaust pipe off of the vehicle so you can properly prepare all of the gasket surfaces (flatten them out). From the picture, it looks like the exhaust pipe flange is not flat, so sealing with a new gasket would be iffy. In this case, you would need the flange gasket and the manifold-to-engine gaskets. It would be difficult to do this in the car. Only my opinion - others may differ. good luck...jack
 
In my opinion if the exhaust manifold is not leaking at the block don't break something that doesn't need fixing..., however the exhaust pipe connecting to the exhaust manifold appears that whom ever tightened it up tightened it too much causing the two ends to bend therefore allowing space in the center where it is leaking and it appears that flange from the photo from what I can tell is welded to the exhaust pipe, so if you can manage somehow to get that flat, I would take a ruler or level some flat plain and set it across the top of that exhaust pipe flange and if you can see daylight it's bent, so flatten it best so you cannot see daylight if any at all.

404262915.jpg
 
my apologies, and of course after you have flatten'd to best of abilities apply the new gasket and tighten just to what you think is enough as to not bend it again, I know sounds easier than one always thinks, when something should be just that easy.
 
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