Anyone know if there's much of a flow difference between the rear outlet style exhaust manifold on a 98 5.9 Magnum and the center outlet style manifold on the 1990s Dodge V8 vans? Where the van motors Magnums too?

Still ironing out the last few details before I start the 5speed swap into my 98 5.9 Grand Cherokee.

The driver's side manifold outlet is right where the Dodge NV starter will need to go and it's too tight to do any rerouting. I've seen pix of the V8 Dodge V8 van center outlet style exhaust manifold and it looks like that might work with a bit or rerouting.

I know there are some headers that might work for me but I'm not in a position to do that at the moment.

Any suggestions or info is appreciated - John

 

where are you getting the conversion parts from? thought all 5.9's had the auto behind them and were internally balanced...

 

There is a special Magnum 5.2/5.9 V8 exhaust manifold for Jeeps
that is different than the Ram/Dakota versions.

Steve Dulcich did some manifold testing but it does not include the Magnum manifolds or Jeep variant, but you can make some guesses after looking over the results:

http://www.moparmusclemagazine.com/t...ust/index.html

My guess is that the center outlet from the van design would flow a little worse.

 

I thought the 5.2's were internally balanced and the 5.9's were externally balanced!

 

5.9 external, 5.2 internal.

I'm planning on using a Dodge or Jeep NV 5spd and a Ram 5.9 flywheel and PCM.

There were 5spd5.9 Rams and I'm pretty sure Dakotas too. I think the Daks were RTs w/ 2WD only, not sure which trans they used. The 4WD Rams used the NV4500.

The choises are: NV4500 from a 5.9, NV3500 from a 5.2 Ram or a Jeep Wrangler NV3550 with a 3.9 AX15 bellhousing. I think the NV3550 might have been used in some Dodges, not sure though.
The Jeep build is going to be for street performance use, not offroading so I'd rather stay away from the 4500's "almost granny" first gear. The 3500 and 3550 have about the same first gear ratio.

I've seen three other Jeep ZJs (93 - 98 Grand Cherokees) converted to 5 spds. One was a dedicatedoff road build and the specs didn't really apply to my swap. One was a 5.9 LTD like mine with the 4500. It fit well as far as the shifter location. The other was about a 94 5.2 but with a built up 5.9 swapped in. That had the NV3500 as I had planned on using but the shifter came through a few inches forward of the stock location and the front of the console had to be cut or removed.
Now I'm hoping the NV3550/AX15 bellhousingcombo might give me the gears I want and the location I want but I haven't looked into it yet,

One of the bigger problemsfor this kind of swap is that the Jeep Magnum motor's starter ison the passenger side, the opposite of the Dodges. Since that is also where the front d/shaft is there isn't a lot of room and the stock driver's side exhaust exits right where the starter needs to go.

I'm pretty sure the 4500 swap used Sanderson block hugger headers and the 3500 swapactually had the starter pocket moved to the other side! Not sure if they moved the original pocket or added one that was cut from another tranny.

As much as possible, I'd like to build this "as Jeep would have done it" so I'm looking at manifolds to begin with. Besides, that's what the budget calls for :-)

HankL - Thanks for the tip. Good article. Actually the center outlet style I was planning on using looks to be the second one they tested, the one with the ridges. I found them on ebay as Dodge van w/Magnum motor driver's side manifolds. Seems like it flows pretty good from their testing but like you said, they didn't test it against the newer Jeep and Dodge manifolds. That looks like the only thing that might work for me and even that will be a squeeze. If I have to sacrifice a few HPs that's OK, I should get them back through other mods.

Thanks for the info folks - John