Challenger Exhaust Manifolds

[sdcbowler]

Hi Members,..

Came up against a new issue when working on my exhaust system....'70 Challenger, 426 Wedge. Manifold casting numbers are Left: 2951865 / Right: 2899879. Car was originally equiped with a 383/2 barrel. Exhaust pipes are 2.25 dia purchased from an aftermarket supplier. Started on the driver side first, and completed with no issues. Then went to the passenger side and found the flange on the exhaust manifold was smaller than the flange on the exhause pipe. Although this did not make sense to me, I had to come ask the forum if anyone else had come across this issue ever before.

My engine rebuild gasket set came with the exhaust manifold to exhaust pipe gaskets. I placed the gasket on the exhaust pipe and it clearly fits. I then held the gasket againt the exhaust manifold mounting flange, and you can clearly see that they do not match...... You can see in the pics. The first and second pics are of the exhaust pipe and gasket sitting on top. The third pic is me holding the gasket against the exhaust manifold flange.

Not sure where to go from here. Any advice or reasoning would be greatly appreciated,
Thanks

 

[Chryco Psycho]

Well I am nt sure who you bought the pipes from but I always had to give the manifold casting # to make sure they matched , clearly you need a different manifold now or have the pipe reworked with the matching flange .

 

[moparleo]

Agree, contact pipe supplier.

 

[sdcbowler]

The pipes came with the car when I purchased it many years ago so they were basically free. What I am confused about is why are the flanges on the manifolds not the same size.

 

[sdcbowler]

Agree, contact pipe supplier.

Moparleo,

You are also suggesting the pipe is incorrect. Let me ask a plain question. Shouldn't the flanges on the exhaust manifolds (left and right) be identical, or is the driver side supposed to be bigger?

 

[Mr Cuda]

The problem, and the key to answer is, the car was a 383 2bbl.
Chrysler had the cruel sense of humor to mix standard log manifolds, with the hipo drivers, because the log won't fit.
Buy a magnum right side manifold, and use the pipe you bought.

 

[sdcbowler]

Well I am nt sure who you bought the pipes from but I always had to give the manifold casting # to make sure they matched , clearly you need a different manifold now or have the pipe reworked with the matching flange .

If these are my two options, I am clearly getting the pipe modified since it is not yet installed.

The problem, and the key to answer is, the car was a 383 2bbl.
Chrysler had the cruel sense of humor to mix standard log manifolds, with the hipo drivers, because the log won't fit.
Buy a magnum right side manifold, and use the pipe you bought.

Mr. Cuda,

Can you tell me what is a 'log' manifold? Never heard that term before

 

[Chryco Psycho]

There are 2 types , the upswept highrise performance manifold all of the HP engines had , & the "log" type that non performance engines had .
I can't tell from you pictures which one you have but I would change to HP maifolds if you do not have them

 

[pschlosser]

Forget the "log manifold" thing, as it refers to straight low performance exhaust manifolds - they look a little like a small log of firewood to some.

The casting numbers you give are for the high performance exhaust manifolds, and these are the ones you want.

If I recall correctly, high performance cars (440-4, 426-8) came with 2.5-inch exhaust pipes, and the lower performance ones (example 318 car) had 2.25-inch.

Your 1970 383-2 may have come with 2.25 exhaust, but you're making a high performance car, now.

I believe your exhaust manifolds will be at 2.50-inch. If your exhaust system is at 2.25, you may need to have the flanges changed,

 

[Mr Cuda]

The casting numbers in your opening post are correct for performance manifolds.
There is no way the right performance...879 will have a 2.25 exhaust flange.
I'm going to propose that you have a ...876 like the one pictured.
The fact that you have a 426 wedge is just confusing the issue, as no 426 came with performance manifolds, except max wedge. And you'd know if you had those, plus they wouldn't fit.
So you probably have what the car came with, time for a new right manifold to fit the pipe.

 

[pschlosser]

Good call, @Mr Cuda

The low perf (log-style) manifolds do have similar casting numbers to the high perf ones.

 

[sdcbowler]

I suppose that is highly possible. I was trying to avoid removing the manifold. I guess I will remove it on Saturday because I am anxious to get to the bottom of this issue.

Thanks to both of you f

Forget the "log manifold" thing, as it refers to straight low performance exhaust manifolds - they look a little like a small log of firewood to some.

The casting numbers you give are for the high performance exhaust manifolds, and these are the ones you want.

If I recall correctly, high performance cars (440-4, 426-8) came with 2.5-inch exhaust pipes, and the lower performance ones (example 318 car) had 2.25-inch.

Your 1970 383-2 may have come with 2.25 exhaust, but you're making a high performance car, now.

I believe your exhaust manifolds will be at 2.50-inch. If your exhaust system is at 2.25, you may need to have the flanges changed,

When I bought the car many years ago, it was in disrepair. I would not doubt that the previous owner used whatever parts were at his disposal......correct or not. I will try to locate a HP manifold.

 

[sdcbowler]

The casting numbers in your opening post are correct for performance manifolds.
There is no way the right performance...879 will have a 2.25 exhaust flange.
I'm going to propose that you have a ...876 like the one pictured.
The fact that you have a 426 wedge is just confusing the issue, as no 426 came with performance manifolds, except max wedge. And you'd know if you had those, plus they wouldn't fit.
So you probably have what the car came with, time for a new right manifold to fit the pipe.

View attachment 106705

Mr Cuda,

You were absolutely correct. The RH manifold is a LP 2899876 (log). My question to you and the forum is, would the HP 2899879 fit in my engine bay without any modifications? The car does have factory a/c.

Thank you

 

[pschlosser]

My question to you and the forum is, would the HP 2899879 fit in my engine bay without any modifications?

Yes, it should fit in the engine bay with your 426 wedge. And the position and angle to the exhaust flange should match that of your prior manifold.

 

[sdcbowler]

Yes, it should fit in the engine bay with your 426 wedge. And the position and angle to the exhaust flange should match that of your prior manifold.

Thanks much, pschlosser
Tomorrow The Inland Mopars Club is hosting a 'Mopars in May' Chrysler Car & Truck Show in Ontario, CA. There will also be a swap meet. Maybe I will be fortunate enough to find one. I know they are getting very hard to find. Found one here on febo. I am waiting for the owner to get back to me concerning shipping costs to my area.

Have a good Sunday

 

[sdcbowler]

Hey Guys,
In case you or someone else may want to know.....when I went to the car show last weekend in Ontario. One guy put me in touch with a guy from Delaware who he says is licsensed by Chrysler to manufacture the exhaust manifolds. I recently puchased a 2899879. He offers them in the two different date codes, and also without a date code. I posted pics of the one I received. I didn't put his info or website information because I did not know if it would violate the forum rules. Cost was $395. Driver side is about $20 less. Total cost with shipping from Delaware to California $473.00.

 

[Xcudame]

Mr. Cuda, you're spot on. I myself being the owner of a 383 Challenger (originally a 2-bbl) since I was 19 never understood why the driver's side got the HP exhaust manifold while the passenger side got an odd ball LP manifold. What where they thinking? It is a cruel joke! Needless to say, one of the first things I did was swap to a HP passenger side exhaust, swamped in a HP 383/440 cam, lifters and valve springs and a 73 400 intake manifold with a Thermoquad! Certainly not a true 383HP, but I can run 85 octane garbage gasoline! And there's something about those huge secondaries opening up that gets the pulse rate up!