5.2 magnum exhaust manifolds?

[Valvebounce]

Hi,
Before I make my post, I'll state that I did do a search, but didn't find what i was looking for?
Also that magnum equipped vehicles were never sold here from new.

Any, I have a 318 engine which I would like to fit a Wuhan war whistle on. (The engine is close to being ready to assemble, and will get appropriate ring gap etc) I'm semi copying a friend's set up. He's running magnum truck exhaust manifolds, swapped left to right. With the cones ground of, to make the mounting flanges flat.
He sent me link to Rock auto for the manifds he used. (Cheap enough)
Amongst a pile of spares, I found some 340 exhaust manifolss off a challanger. (Not the HiPo ones which are highly desirable?)
One of them is the rear discharge type. I could swap that to the opposite side easy enough. (Meaning I only need to order one manifold) while googling manifolds one time, I happened across one of Richard Holdeners videos from 4-5 years ago. In it he states, that one year Magnum was bigger in the collector/discharge?
Since I can't just go to a junkyard and look for myself, I figured I'd ask the FABO Hive mind? (This forum is the "one source of truth" for reliable accurate information imho)
Is this common knowledge? More importantly, is there any gain from trying to source a factory one (or pair?) Or just grabbing one off rock Auto, and sending it?

Lastly, since they're not the HiPo version, there's nothing special about the 340 manifolds is there? (Better ask before deleting the cone off one)

Any help or advise is appreciated.

 

[Illahe]

I believe the driver side 340 is fairly similar through the years for A Bodies. IIRC one has a flat flange with 2 1/4" id outlet and another has the cone cast into the outlet.

Accurate Exhaust in Roseburg Or. has a lot of knowledge regarding exhaust manifold casting No. and application. They may be able to answer your question.

As far as magnum exhaust manifolds, I recall a 5.9 Dakota "hi-po" that had a 3.92:1 rear ratio. They may have come with a "hi-po" exhaust package. Worth looking into.

 

[Valvebounce]

I found the video again.

 

[Kern Dog]

That guy is smart but also a bit annoying.
This does validate what some people claim.....that headers on a mild engine may not be worth the effort. What was that....10 HP over the manifolds with the smaller flange? BIG D E A L !!
I love the sound that one gets with headers and free flowing mufflers but the juice has to be worth the squeeze.

 

[gdonovan]

Hi,
Before I make my post, I'll state that I did do a search, but didn't find what i was looking for?
Also that magnum equipped vehicles were never sold here from new.

Any, I have a 318 engine which I would like to fit a Wuhan war whistle on. (The engine is close to being ready to assemble, and will get appropriate ring gap etc) I'm semi copying a friend's set up. He's running magnum truck exhaust manifolds, swapped left to right. With the cones ground of, to make the mounting flanges flat.
He sent me link to Rock auto for the manifds he used. (Cheap enough)
Amongst a pile of spares, I found some 340 exhaust manifolss off a challanger. (Not the HiPo ones which are highly desirable?)
One of them is the rear discharge type. I could swap that to the opposite side easy enough. (Meaning I only need to order one manifold) while googling manifolds one time, I happened across one of Richard Holdeners videos from 4-5 years ago. In it he states, that one year Magnum was bigger in the collector/discharge?
Since I can't just go to a junkyard and look for myself, I figured I'd ask the FABO Hive mind? (This forum is the "one source of truth" for reliable accurate information imho)
Is this common knowledge? More importantly, is there any gain from trying to source a factory one (or pair?) Or just grabbing one off rock Auto, and sending it?

Lastly, since they're not the HiPo version, there's nothing special about the 340 manifolds is there? (Better ask before deleting the cone off one)

Any help or advise is appreciated.

The early 91-92? manifolds had a larger outlet, I might actually have a set here.

 

[gdonovan]

That guy is smart but also a bit annoying.
This does validate what some people claim.....that headers on a mild engine may not be worth the effort. What was that....10 HP over the manifolds with the smaller flange? BIG D E A L !!
I love the sound that one gets with headers and free flowing mufflers but the juice has to be worth the squeeze.

Will depend on the package; My Duster picked up in excess of 50 HP going from small manifolds to headers. Really showed up on the timeslip.

 

[Kern Dog]

Uhhh...Notice the part where I stated headers on a mild engine.....

 

[gdonovan]

Uhhh...Notice the part where I stated headers on a mild engine.....

Notice the part where I stated will depend on the package.
I have a 5.9 Magnum with a dual plane intake, it's a fairly mild package.

 

[fshd4it]

Valvebounce - clean out your inbox.

 

[4mulas]

I love the sound that one gets with headers and free flowing mufflers but the juice has to be worth the squeeze.

And entrance fee now. Admission has gone way up so I choose carefully where I go now…

 

[Fury1969WI]

1992 and 1993 Magnum V8s had the larger exhaust pipe flange. Also, there are a few quirks between 1992 and 1993, pic from some off parted trucks. (yes, that '93 was crusty Wisconsin Ramcharger).

 

[Kern Dog]

Holy crap....the 1993 manifold is rusty!

 

[Valvebounce]

This is why I'm on this forum.
Regardless of the subject, somebody will know the exact details.
I presume those extra parts on the '93 manifold were added for strength? (Not uncommon for parts to evolve like that) I wonder if the '92' suffered failurws/warrantee issues to cause them to need to be added?

 

[Valvebounce]

Holy crap....the 1993 manifold is rusty!

Hey, hey, rust is lighter than Carbon fiber!

 

[Fury1969WI]

This is why I'm on this forum.
Regardless of the subject, somebody will know the exact details.
I presume those extra parts on the '93 manifold were added for strength? (Not uncommon for parts to evolve like that) I wonder if the '92' suffered failurws/warrantee issues to cause them to need to be added?

that's my assumption too - it's the Driver Side and those twists and turns around.

The PS didn't seem to change all that much those years and note no lower supports cast in.

I do not recall if the EGR boss carried on but i think at some point that went away. I don't think you'll find the wide throat manifolds without the egr pipe provision.

Holy crap....the 1993 manifold is rusty!

Yep, for sure "some rust." LOL. Lots of good parts were saved!

 

[Valvebounce]

It's not too had to plug the EGR port.

 

[dartski]

I was lucky enough to find these super clean manifolds for my project. Both dated late 91 so maybe 92 pieces.
These are the 2 1/8 outlet type.

 

[Valvebounce]

Well,
After starting this thread, I've been speaking to @fshd4it .
Turns out he had a pair of manifolds, and was packing up to move.
So despite being on the other side of thw world, today he handed them to be personally here in New Zealand!
(What a bloody champion!)
Had a great old yarn with him today too.
THANKS!

 

[Michael Harrington]

Here is a side by side of the desirable larger outlet VS everything after.