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I just purchased my '88 Grand Wagoneer. It came with a set of Hedman Full Length/Long tube style headers.

I am fairly certain that the factory Y-Pipe was not designed to fit a header with a flange/collector in the same location as these headers but I figured I would ask. I do not have a factory Y-Pipe to look at, so I can't reference anything. That's why I'm asking you all!

Will a factory Y-Pipe bolt up to a set of Hedman full length headers? I assume the full lengths put the collector much further down towards the ground, therefore rendering the factory Y-Pipe useless unless it is modified, but I thought I'd ask.

If the factory Y is useless...is there an aftermarket/performance version recommended for the Hedman full lengths? Or is custom the only option?

I want to start daily driving this thing and the first thing I need to do is put exhaust on it. Is there a recommended size for the AMC 360? I am planning to come out of the headers, into a Y, and then single exit out the side similar to factory.

The engine is stock other than an edelbrock performer and edelbrock 600 carb (1406? Can't ever remember the number...)
As far as I know heads and internals are all stock but I haven't opened it up yet to verify.

Thanks in advance,
Shawn

Nope, their collector locations are very different. If you have the shorty headers, a lot of those are meant to be in the same location. But the long tubes are very different.

I do not know of any after market bolt in exhaust systems. I have always gone to a local exhaust shop and had them fab up the exhaust for me.

Stuka wrote:Nope, their collector locations are very different. If you have the shorty headers, a lot of those are meant to be in the same location. But the long tubes are very different.

I do not know of any after market bolt in exhaust systems. I have always gone to a local exhaust shop and had them fab up the exhaust for me.

That's exactly what I assumed but figured I would ask.

Is there a reason to go 2.5"-3"? I know free flow is important, but too much can hurt. What works best on these 5.9s with stock internals and just upgraded fuel systems?

Well, most of the time that people claim they "lost power" due to an exhaust that was too large is because they did not retune the fuel delivery side of things. A freeer flower exhaust requires retuning the carb, and really it also requires a more free-flower air intake. But re-tuning the carb is the most important. A 3" exhaust is not too large for a 5.9L engine. Most newer cars with 3-4L engines are using 2.5" from the factory. A 2.5" will work fine, and may be a bit quieter. But if you are going with long tubes, you would benefit more from them with a 3". Just be sure to retune the carb afterwards as it will lean out.

id run 2.25 or 2.5" off the headers into a flowmaster Y junction into 3" single with a real long round dynomax ultraflow or magnaflow out to the stock exit location.

Please ignore the loose trans lines and wiring. I dropped everything down so i could clean it all up. Pretty sure nothing is leaking after the previous owner sealed it all up, but there is a significant amount of residual.

Here's a crude photo of the exhaust.
Now on the drivers side, should I make an immediate 90º turn straight across into the passenger side? Or further out before I turn?

How is everyone routing their exhaust around the trans and transfer case?

Also, any issues with the exhaust near the brake proportioning block or fuel lines?

Thanks in advance.
Shawn

Header wrap is your friend when it comes to heat. Helps a lot.

For single exhaust, you pretty much need to cut right over after the collector.


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i put a 90 so the crossover is right infront of the trans crossmember, i can still remove the trans pan fine. then 90 back long the frame. i kept the bottom about flush with the bottom of the crossemmber so its not super close to the trans. but hopefully wont get banged up. id still like to make a heat shield. i have a quadratrac everything is super tight under there for exhuast. i placed the flowmaster Y so the 2 pipes were between the transfer case and frame, the single 3" part of it wouldnt fit. there really wasnt much room to play with since i went with a real long muffler, that slips on the Y and right out of the muffler it kicks up to go over the axle. everything just fit.

ok, first, i'm sorry for digging this old thread up but i'm looking to solve my issue and this is the only thread I can find that's similar.

I currently have long tube headers on my 88. long story short, I have a shop custom run an exhaust with hedman headers part 99250. I went with these because they are super cheap and i'm eventually going to upgrade to better ones but the bank account was getting to stretched so I had to make a bad decision. The exhaust is a 2.5" to a 3" tip with a thrush... I ADORE the sound of it and don't want to stray away but these headers were so cheap I can justify spending lots of money on them.

Things were going well till about a month ago and I had to make a very hard stop and I blew the collector on the DS. threw it on a lift and sure enough the front driveshaft has been striking the headers and Y pipe on large bumps and hard stops. i've read that in order to run long tube headers on my year they would need to altered to fit to prevent this. The original mechanic isn't going to honor their warranty (long story and i'm working on a charge back to remedy this) so I've taken it to another shop. before I listen to what they have to say I want to get this forum's opinion on how to fix this issue.

I've read about a short term fix to cut the collector flange and weld a flex pipe to the header, I know it won't hold up for the long haul but maybe it'll get me a few years till I can afford really nice headers?

The exhaust is a 2.5" to a 3" tip with a thrush... I ADORE the sound of it and don't want to stray away but these headers were so cheap I can justify spending lots of money on them.

thoughts?