JBAIN

I have a 1998 Cherokee 4L and I'm in the process of building a 4.6 stroker. I took a trip to the pick and pull looking for injectors but found a 2000 + intake instead. After removing the intake I got a good look at the 2000+ dual cast iron exhaust manifold. Knowing nothing about it but knowing my stock one is cracked I took the chance and bought it along with the Y pipe. Does anyone have any info on these and will they flow better than my stock exhaust manifold?

SqueakyT1O

i dont know for sure, i would think not considering each half has a cat.

jth877

They flow worse. The switch was to meet emissions standards.

white91

If it is a cali emmisions jeep then it should have small cats just down the pipe and one main cat just after the tranny crossmember. I wouldnt use this one HOWEVER i would use the NON cali jeeps as they only have one cat and two o2 sensors. (1 for air flow and the other to read the o2 levels). In 2000 jeep had to do a lot to cut down on the emissions but to get the power back they made a better flowing intake and exhaust manifold. This is a true 6 to 2 to 1 header design with a 2.5" pipe to the cat. The old style is a 6 to 1 with a 2.25" pipe to the cat. It also had a factory dent right at the collector. How smart is that? not very!!! So to conclude the 2000 intake and exhaust will and does flow better than a stock 84-99 exhaust and intake. But be cautious though, Make sure to use this setup with a lift if you are running a High pinion axle up front. The 2000 jeeps came with a low pinion to clear the 2.5" exhaust pipe. Hope this info Helps

JBAIN

Thanks everyone, and the one I bought has no cats (ohio Junk Yard) and yes I'm running a 4.5 inch lift. White91, you mentioned the O2 sensor locations and I know mine has 2 is this a plug and play swap?

white91

As far as bolting up. You wont have a problem. Not sure where the locations of the o2 sensors are in your Jeep. You may have to lengthen some wiring. I'm sure you wont have to. Good luck.

JBAIN

I was hoping maybe you had done this already..... thanks again you've been an invaluable help.

jth877

The intake change was 99+. I doubt the cast iron flows better than an OEM HO welded steel. The "dent" is controversial. There is a slight dent on the axle side (where it would hit) the crimp is much deeper on the block side. Rumor was that the dent is there to restrict flow and increase torque- I don't know which is true. I do know that many 2000-2001 owners lack the torque of 96-99 models.

When in doubt, just buy the APN stainless replacement header. It's slightly cheaper (and better built) than a OEM knockoff like dorman.

Cybershot

I build my 4.7 L Stroker and had the same problem but oposit way around.

My xj is an 2001 and I swaped the head to an 0630 head from 98 (because the 0360 from 2000&2001 are very weak) The holes are fitting but the ports are not align and the casted header ports are smaller then the earlier pipe headers.

My advice, stay with 1999 er header. They will break at the welding joint, but they are still better then the casted irone once which will smaller your ports and causes some turbulances to your stroker.

TheJerm

I got some input from recent endeavors: (all personal experience the hard way)

The dent in the exhaust down tube is for clearance of the front DS/yoke, my straight replacement now has a dent... This is also the reason 2000/01 are low pinion front axles because now they have the pre-cats in the way. Stupid design to put everything on one side.

I'm running a 99+ intake with an APN header. 1st time i didnt have an issue with bolting them on, then i cracked the header (and causing the dent) with the front DS/yoke and their life time warranty is great. The 2nd header interfered with the #6 intake runner. SO my solution was:

[IMG][/IMG]

I just used a MAP torch and a hammer, pretty easy and took a few tries. Couple thousand miles later no issues. btw i did not dent the header in the vehicle. I would also recommend a flex tube to be inserted on the down tube between the header and cat to further protect the header from cracking.

JBAIN

Thanks everyone, I plan to port match the intake and exhaust so I'd better take a closer look at the cast iron one. That's a good pic of the new style manifold Cybershot but mine doesn't have the cats or the flange at the bottom. It just turns at the bottom and goes under the engine, so I cut it there and had originally planned to splice it into my existing exhaust.

Cybershot

You will manage to get the cast iron header to the existing exhaust. No thought about this. If you place the cast iron header to your head, the screws will fit but the ports are little lower and not in center of you head ports. And the cast iron ports are 3-4 mm smaller on each side.

If you port the cast iron header, check how it aligns with the head. I remember that it was of the center for almost 5-6mm.

Good luck

JBAIN

thanks again Cybershot, If I was staying stock I would probably work with it but since I'm going with a stroker I'll probably just go ahead and buy a Header or weld up my existing manifold.

TJ805

Good thread! I have a 2001 XJ. Does anyone know if I can I put a 0360 head and pre 2000 exhaust, and still pass smog in Ca?

Any advice is appreciated...