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JM Long tube headers, the inside story

62702 Views 236 Replies 43 Participants Last post by  SinCity R/T
OK, we all read the 8 pages of stuff in the "swap" section. So, I wanted to answer a few questions for you guys cause I saw alot of nonsense posted.

First, these are true long tubes. And with that said, these are not a typical 1 hour bolt on. If your Mopars took you 2-3 hours, these won't. If you want a simple install, these aren't for you. If you want serious headers for a serious HP gain and effort spent isn't a big deal, these ARE for you.

So, now your saying, who the hell are you Tanky? I'm one of (I believe ) 2 that tested these headers. Thats right kiddies, I did the 2nd ever prototype test fit and it was done on a 2000 RC RT. Glen Renzoni did the first ever test fit, and he deserves much of the praise as ever since he's input helped the design. Using his instructions he sent me, we made up a basic instruction set for John to give to folks. Trust me, you need these instructions--it helps!! We only found 1 minor thing that the builder fixed ASAP.

What yall don't understand is this set of headers are built by a huge NHRA exhaust builder. Not just anyone built these and a TON of time went into them. From a bone stock RT to a 408 blown, its been tested. Dyno numbers weren't done, but seriously, if you need a dynojet to know the difference in gains over shorty's to long tubes, then I can't help you any further.

So, what did the prototype install net us? For the 2nd ever install, it was flawlessly perfect. However, you must understand this is no TB install or some crap. This takes time. The passenger side will BE close, very close to the transmission pan. You all need to understand what you have in your hands...a designed work of art to go in a MIDSIZE vehicle, space is NOT your friend. You will still have clearance.
The passenger header itself is an absolute work of art, anyone that thinks otherwise has no idea of engine performance. If you looked at the pictures on his headers, you would have noticed bags covering the collector. That my friends, is the trick and design genius to this header. The passenger side will be a tough install and the slip fit #8 (or #6--been awhile) pipe allows for easier install.

Whats involved in the install? Well, i can tell you what worked for us and how we made things go very smooth for us. This is of course, using Glen's instructions to help us along. For the passenger side, your coil needs to be removed and it makes life a ton easier to REMOVE the motor mount. Don't be alarmed by this, its much easier than you think. With the mount out of the way, these headers go in fairly easy. You will need to have a jack on the motor though--duh!
Driver side, was a bitch. Glen had more problems on the passenger side than we did so, not sure here. You need to remove the starter. I will tell you right now, thats a MO-FO especially if you have mopar headers and a floor shifter. space is soooooo friggin tight. It also helps to have a lift handy. These headers are so long, doign this in your garage will be challenging. We did it however, in the garage, to see how difficult the install would go. Jack Stands will NOT extend far enough for clearance. To be honest, we took a 3 ton jack, placed it on the side (under driver's door) and MAXED it out. The truck was damn near a 45 degree angle, but this allowed enough floor clearance to get these suckers in. Trust me, its no easy job. A lift will make life better, but it can be done in a garage if need. Use concrete blocks or something for your jack stands :nana:

I know that was very brief and I can email the exact directions we sent John. I just wanted to touch base with you guys on these headers. They are, in no way shape, or form anything close to GSM garbage. These are true long tubes built by a true NHRA company with over 15 years of experience (IIRC). Its a matter of what you are looking for in your truck. Serious power and gains or not. John has spent a ton of time, money, and effort, along with his friends, to get these headers out to you. To be honest they were almost ready at time GSM came out, but true to John is, he wouldn't release them without testing them on several year models FIRST, something Scott didn't do and the headers hit on 2000 models. Quality is of the finest out there. John doesn't put his name on garbage.

But I can't stress enough the install of them. Don't go into these thinking its a wham bamm ordeal cause its far from it. However, you will have one of the best items out there you can get for a Dakota V8 truck.

If I can be of further help, feel free to ask. I hope all this helps clear some air.
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Pick your poison...

1) John Mercedes 1 3/4" long-tube headers. One actual owner has posted pictures with questionable flange quality. Another owner installed theirs and reports no problems but didn't examine or take pictures of the ports before install.

2) GiSM 1 3/4" mid-length headers. Owners report that the ceramic coating sucks, and there is lots of reports of poor customer service. Collector gaskets fail a lot.

3) KRC/Hooker 1 5/8" long-tube headers. These weren't built for R/T's, but I owned a set and didn't have any problems with them. The only complaint I can think of is that KRC jacked up the price by over $200 since I bought mine.

Beyond that, there really isn't any regularly available mid/long-tube header for the Dakota R/T. PPH's aren't made anymore outside of big group buys, and Jess' headers are significantly more expensive and are not readily available.

Hopefully John will jump in here and give some direct info about his headers, but I would otherwise ask that people refrain from talking shit about any product they haven't owned on their own truck. Anything else that should be prefaced with "I heard..." should be taken with a grain of salt as potential rumor and not fact.
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Here's my old PPH's:


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One more of the PPH's

Unfortunately I can't find any flange pix of my GiSMs or Hookers.


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Danno said:

Jess is one of the NW guys that has no clue what hes doin!...


OK Ill go back to sleep now.

I dunno why you or anyone else keeps bringing up Jess' headers - you can't just run out and buy a set (last I heard on Delphi it was at least 2+ months before the next set gets built), they're custom-made for each truck, and they certainly cost a lot more. It's really cool that you NW guys have managed to get a great group of owners together and have parts/labor sources (ie: mike, jess, brem dodge, etc.) in your local area, but you can't even begin to compare custom-built stuff vs. what these guys are trying to buy in a regular production environment.

I would also hardly call your group of trucks anywhere near the ideal platform for general product development - you guys have some of the most one-off setups out there - Lloyd's probably the closest thing you have to being "standard".
I don't wanna even come close to touching the vendor clique, danno's lifters, etc. subjects - completely irrelevant to me in this thread. I just think people are getting too far off subject here with the flames and custom parts and whatnot.
John fwd'd me this photo to post since another moderator decided to close the thread.

This photo is Glen Renzoni's SE Performance long-tube header.

note from John:

all is perfect but i would take a trimmer and take the slanted part of the
header gasket off. they must have supplied the older 340 - 360 LA motor
designed header gaskets which have that small dog legged port design unlike
the Oval Magnum ports.


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