I seem to recall, a few years back, that someone was trying to, or had installed, a set of the '92/93 Dakota exhaust manifolds in an A-bdy. Purportedly, these manifolds flow better than the '68-70 340 Magnum manifolds. Does anyone have any information on this mod?

With the rear dump, I know there are going to be fitment issues, but I sure don't want to keep the original 273 driver's side manifold on my ride.

On a similar topic, when a buddy was finishing his 73' 340 Cuda, he couldn't find an affordable driver's side manifold. He was working in the parts department of a Dodge / Jeep dealer at the time. He ended up using the manifold from (I believe) a Magnum powered Cherokee. Brand new and cheap, well under $70 at the time.

Thnx, Mike in FL

Thnx, Mike in FL

The Jeep manifolds occupy the same area as the starter on a mopar, the jeep V8 starters were on the wrong side.

I had a set of the early large port 1992 magnums on my 68 cuda and there were no fitment issues, columb shift auto manual steering/brakes.

I started a thread about the Magnum manifolds a couple of years ago. I was working on the car that inspired my screen name. The factory 340 manifolds were expensive then, (STILL are) so I was looking for alternatives. I bought a pair of 5.2 Magnum manifolds from a 92 Dakota. This is what I found:

The RIGHT side clears by a mile and is a great improvement. The internal passages are larger than any other 273/318/360 manifold that I have seen and seems only slightly less efficient than the 68-71 340 version. The RH Magnum unit has a rear dump that allows the exhaust pipe to be connected just above the oil filter. This bypasses the crappy zig-zag around the idler arm and center link. The exhaust pipe just goes down the path of the firewall and under the car. ONE bend instead of three.
The LEFT side is not so easy. These manifolds are mirror copies of each other, so that rear outlet on the drivers side puts it too close to the steering column. Angle milling the mounting flange may help, but the outlet will still point toward the clutch cross shaft in manual trans cars. On column shift automatic cars, same thing. The only way I could imagine it working is on a FLOOR shifted automatic.

Drivers side magnum manifold will not fit with PS in an a-body if I remember my notes correctly.

pic of drivers side Jeep Magnum manifold

pic of passenger side Jeep Magnum exhaust manifold

Pic of driver side Ram Magnum exhaust manifold

pic of 1994-1995 Ram Magnum Exhaust Manifold Passenger side,
with EGR port and block off plate visible

When the 1992 Ram pickup Magnum 5.2 V8 engine came out,
the official Dodge Press Release of the new engine design features called these exhaust manifolds 'balanced flow'
so at least some effort was made to even out and match the exhaust capacity of each cylinder, perhaps to get the air to fuel ratio balance right for emissions purposes.

In 1994 the internal passages were made smaller than the 1992-1993 outlet of 2.125 inches,
perhaps to increase backpressure and internal EGR, or perhaps get more exhaust gas to flow up the tube when the EGR valve called for it,
either would slightly decrease NOx pollution, which got a tougher and lower standard in 1994.
It is also possible the backpressure was increased as a way to get a cold engine up to operating temperature quicker, as the cold engine start EPA test is the hardest section for automakers.

Max SAE HP on the 1994 Magnum 5.2 declined by 10 HP from 230 to 220,
although other engine specs such as
retarded ignition timing,
richer full throttle air fuel ratio for cat overheat prevention,
or a different catalytic converter flow rating,
could have equally or in combination caused the horsepower decline.
At the same time as the max HP dropped in 1994,
the Magnum 5.2 V8 peak torque increased from
1992's 280 ft-lbs to
295 in Dakotas and
300 in Rams.

In 1996 with the first year of OBD-II
the EGR valve system was eliminated,
a new and better "Three Way Catalytic Converter" with more NOx reducing ability was fitted,
and a year later on the Indy model Rams a less restricted exhaust led to a 15 HP SAE advertised gain on the Magnum 5.9V8
... but the exhaust manifold internal passages were not enlarged back to 1992-1993 size,
nor were they as far as i know in later years up to 2003.

This brings up the possibility that the exhaust manifold were changed to get thicker cast iron walls more resistant to cracking, especially at the flanges,
but I have never read a post by any 1992-1993 truck owner complaining of cracking on either side,
but maybe it was cracking (or core shift) on manifolds at the iron foundry leading to an unacceptably high casting reject rate.

I scoured the tech archives and no listing, so what are the casting numbers, please? Of the best manifolds. Are there Jeep manifolds that are worth pursuing? I seem to remember that they were more contorted.

And as I have asked in the Trucks page, anyone put these into a Sweptline?

My manual steer hydraulic clutch '64Dog might be an ideal location for some.

R.