383 Exhaust Manifold Question

BLUPORT

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On the passenger side manifold, it looks like there are 1 or 2 nipples on the manifold. I'm assuming this is for some type of pre-heating equipment that is no longer on my car? Are these actually holes going into the manifold? I'm asking because I hear a muffled fart noise that sounds a lot like an exhaust leak over there, and every time I drive the car, I smell like exhaust- even more so if I have the fresh air vents open.

So, if these ARE open ports into the manifold, can I just have them welded closed while my exhaust guy checks over for other leaks?

68 Newport 383/727, for those who don't know already.
 
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Help us by telling us the year of your car or engine, and better yet the casting number from the manifold. Looks like a 68 but let’s not guess.
 
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Help us by telling us the year of your car, and maybe even the casting number from the manifold. Looks like a 68 but let’s not guess.

Updated my OP. 68 is correct. I don't have the casting number on hand.

How about a picture?

As requested. Circled in red, with yellow arrows pointing to the two nipples... Everyone always wants pictures when I mention nipples...

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One is the stop for the travel. One is the pivot shaft for the heat riser. It can leak there, it is a shaft and bushings with no seals.

Move it up and down and see if it’s loose, or rattling. Carefully feel around it with a cold engine running to see if you can feel exhaust leaking out. Don’t burn your hand exhaust system heats up real fast. Don’t do this on a hot engine.

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Updated my OP. 68 is correct. I don't have the casting number on hand.



As requested. Circled in red, with yellow arrows pointing to the two nipples... Everyone always wants pictures when I mention nipples...

View attachment 276609


Zoomed

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I believe that is part of the heat riser system, its missing the cast wheel and spring. It closes a flapper valve to direct heat up into the intake manifold for faster warm up.
 
JDX, 1970 and newer had a cast “wheel”. The shaft went front to back in the manifold. Top photo

1968 had a stamped sheet metal piece. Blue ports is missing, but that doesn’t make it leak. 1969 and older has the shaft going side to side like this picture. Bottom photo

If a car is missing the cast “wheel” or the stamped piece missing it won’t make the exhaust leak.

A3F714A4-E989-4ABA-9FE0-25A2107C5E03.jpeg


8EE9DA72-7B73-4F15-9935-27A0838B5E1F.jpeg
 
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Apologize to use your thread, but since its about the 383 exhaust manifolds, I will jump in. I snap in half one bolt on the passenger side, all the way on the left side next to oil dipstick holder. There is not much of space, so I will probably end up with the fender removal to gain some access to get the rest of the stud out.

But first, I need to buy a new sets of the studs and just want to make sure, I choose the correct one. I have a standard exhaust manifold, the drivers side is PN 2463107 and the passenger side is PN 2532464.

Are these the correct studs? Or can you recommend any better package?
12 New Exhaust Manifold Studs BIG Block Mopar 361 383 400 440 3/8" Set Dodge BB | eBay

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Apologize to use your thread, but since its about the 383 exhaust manifolds, I will jump in. I snap in half one bolt on the passenger side, all the way on the left side next to oil dipstick holder. There is not much of space, so I will probably end up with the fender removal to gain some access to get the rest of the stud out.

But first, I need to buy a new sets of the studs and just want to make sure, I choose the correct one. I have a standard exhaust manifold, the drivers side is PN 2463107 and the passenger side is PN 2532464.

Are these the correct studs? Or can you recommend any better package?
12 New Exhaust Manifold Studs BIG Block Mopar 361 383 400 440 3/8" Set Dodge BB | eBay

View attachment 279977

Hi there,
I'm experiencing very similar concerns as you on my '67 Monaco 383 Wagon.
I ordered these - Chrysler MOPAR V8 Exhaust Manifold Header Bolts 3/8 x 1.1/4 inch Cap Head Kit | eBay
... not sure if studs you've found & 3/8" x 1 1/4" hex bolts I've found are interchangeable though....? and if the length is right, also come in shorter 1"? (My passenger side exhaust manifold is blowing badly along the top & wish to replace the gasket, but need the right bolts/studs first)
Also, my heat riser appears complete & working but leaking gasses out of the shaft holes - Help?

Any help and advice would be much appreciated as always...
 
@DJAstral

1) Leaking gasses out of the shaft holes is common - there are bushings available (likely from www.dynamicrenovation.com) that take care of that issue. There is a special lubricant that is supposed to be applied periodically to prevent the bushings from wearing out. Not sure where to get that anymore...

2) While the bolt kit you ordered might work, they're definitely not correct for exhaust manifolds. The manifolds never originally had gaskets under them FYI, and you may be able to get by having someone dress/plane the manifold to remove any high or low spots if there are any. However, good quality gaskets can take care of that issue temporarily too.

@69_topless - this is the correct kit for your car: Fits 68-74 383 400 440 Exhaust Manifold Fastener Hardware Bolts Nuts Studs | eBay

@DJAstral - for what it's worth, that kit will do it for your car too, although some of the studs may be longer than you need.... I would re-use anything I could salvage from the originals if there's a difference.
 
Unless you live in country that gets REALLY cold, you won't need or miss the heat riser if you have it cut off and the holes welded closed. I've done so on my Newport, and the two previous cars I owned. However, I live in a place where I can drive all-year-round, with weather rarely getting below 40*.
 
If the valve shaft in the manifold is worn it will leak exhaust like you describe, minor but annoying.

Also, be carefull "resurfacing" your manifolds. I took a set of HP manifolds to a machine shop for truing up and they removed .080 from the right side manifold. It barely fit back on and I could not access the bottom valve cover bolds with it in place.
 
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I freed my heat riser with penetrate. How do I know if it works properly?
Sorry to jump on your post.
 
JDX, 1970 and newer had a cast “wheel”. The shaft went front to back in the manifold. Top photo

1968 had a stamped sheet metal piece. Blue ports is missing, but that doesn’t make it leak. 1969 and older has the shaft going side to side like this picture. Bottom photo

If a car is missing the cast “wheel” or the stamped piece missing it won’t make the exhaust leak.

View attachment 276618

View attachment 276619
That’s interesting, my ‘68 Polara 383 2bbl has the cast flapper, I am not sure of when the exhaust manifold would have ever been replaced. To my knowledge the first time the exhaust manifolds came off was in ‘85 when I re built the heads in high school shop class.
Cast in number is 2399876-1
Block is original with the correct date.
EB222FAC-2D57-432F-9170-1405A33D05E7.jpeg

17F3D3FE-63ED-4DBD-BA48-5D49935E2FEA.jpeg
 
2532464 is for 68 383 2 bbl RH.

2998XXX exhaust manifolds start in 1970. I don’t see your exact number
 
2532464 is for 68 383 2 bbl RH.

2998XXX exhaust manifolds start in 1970. I don’t see your exact number

From the TTI website, manifold casting numbers, I misread the 8 as a 3, so mine is 2899876 (somewhere between 65 & 73)
Is there any list that ties the casting number back to the P/N in the parts book as the casting numbers are not the same as the part numbers.

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