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JM Long tube headers, the inside story

62700 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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Devilbrad said:
OK, so I rarely post on here, but I had to make a post. I'm usually consumed with my Dakota/Ram board that is geared more towards actual go fast trucks, as opposed to show trucks. A thread started on my board about these headers and a couple pics were posted. I refrained from replying and asked a couple of friends in the racing industry what they thought. I am sorry to say (and the answers were what I expected), but these headers are fucking junk. Look at the port openings!! What are those lumps sticking into the exhaust air stream??? Its like putting peanut butter into a straw and trying to exhale. Not one single port matches any Mopar small block head ever made. Hell, not one single port even looks like another. Why would anyone make something like that and actually ship it in that condition?? I guess owning an R/T is more of a "its pretty!!!" experience than a "its fast" experience. If thats the case, then you have found the earrings for your motor! Cant wait to see what these guys will sell you next! Pic I am talking about below.

I refuse to comment for fear that I might get struck by lightning.. .BWHAHAHA

Thanks for saying what Ive been thinking Brad... and 2.5" collectors? Gimme a break....

WraithR/T said:
Well, I had PPH's before the long tubes. The PPH's were great on torque. Noticable right after install.
As for the long tubes. You can't really notice much torque loss on the low end. There is some though. Which I didn't mind too much as I have a more stable launch now. You definately can feel a change on the mid to high end. My truck will actually pin me in my seat at the 3-4 shift. Which with a factory automatic is saying a good amount. I guess the way to put it is the powerband is more equal instead of being all low end torque like the R/T's are out the box. If you have any other questions, let me know. I'll answer them the best I can.
Most of that top end gain is from the 4 into 1 vs the try y design. And the larger primary diameter as well.

I got the same gains when I went to the GS's from the PPH headers on 2 of my trucks. Next step for me is 1 7/8" stepped into 2" tube headers... for my lil ol 360 ;) These motors ( LA's too ) LOVE exh sizing....

SB Chevs these arent ( which do tend to like a smaller primary and collector )

mtlcafan79 said:
Dont bother, he knows everything...

Tanky said:
Bigger isn't always better my friend. Kinda like saying the louder it is the faster it is.
Guess you guys missed all the exh/header sizing testing and ET gaining we did up here in the NW the past 2 years eh? I think between Josh and I, we have used EVERY header ( Except the Hookers, and now the JM's ) made, including a set of custom 1 7/8" stepped to 2" headers going into a dual 3.5" collectors... on a 360 that at the time, was just a mild cam heads ( stock cam and heads in one case ). Every time we upped the tube dia on the headers, we gained ET and MPH ( Torque and HP... ) We went from Gibsons, PPH's, GS's, and then the custom ones on 5 different trucks ( 2 of mine, Josh's, Jess's and Brad's ) We all have ended up at the larger tube headers, with the 3.5" dual system. Go look at the timeslips here...


Jess is the top on that list. Brad is #3, Josh is #9, and I am #11 and #19.....

Jess's combo was a Vortech'd 360 w/ 2.02 RT heads, KRC 236 Cam, in a Gen2 CC. Brads is pretty wild at this point, his runs are all NA. Its a 360 w/ W5 heads, but at the time we were testing he was running 2.02 RT heads. Josh's truck was a mild 360 w/ 1.92 RT heads. ( FYI both Josh and Brad were running V&M heads... ) I was the only one on the stock shortblock in the crowd on both of mine. First truck is a 2.02 RT heads 230/240 cammed 360. The second truck is a STOCK heads and cam truck....

When I went from the MP headers on my purple truck, to the GS headers, I stayed with the same exh system ( 3.5" single ) And I went from 11.95 @ 118 to 11.59 @ 118. The single 3.5" is the holdback right now, but the larger tube of the GS headers, with the larger collector, allowed me to make more torque than the MP headers.

When I did the same switch with the black truck and stock heads, I went from a 12.20 to a 12.02 ( heads became the limiting factor... no portwork at all on them ).

Longtubes have their place... but I think the boat was seriously missed on these headers. They will be great for the mild bolt on crowd... but ANYONE making over 400 RWHP is going to need more that what is being offered here. And that includes most of the 150 shot crowd, as well as the better blower combos. Wont even get into the poor 408 crowd....

But hey, what do I know ;) I just assemble my own stuff...

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Good for you, Im sure all that aircraft knowledge helps a ton when building your truck :jester:

Jess works in the aircraft industry too... so his knowledge has as much validity??? hahahaha

And your dyno claims are going to be subject to the same issues. Correction doesnt mean BS.. esp on a chassis dyno.

Keep spewing crap, and keep gettin the crowd to follow the masses of JM buddies, meanwhile, we will just keep getting faster and posting up how to do it. Those that want too will... those that like spending money for no good reason... well those are your friends arent they?

Tanky said:
The truck isn't street legal genious w/o headlights.

The flange was exactly port matched to RT heads, and gasket were custom made for them as well. But don't take my word for it, call SS up and ask them yourself.

Don't run them, I don't care.

To danno, come on man, quit trying to feed BS man. You can't honestly test EACH header on equal trucks and track test them, on the same day. Let me help you out, its called atmospheric differences (temperature, humidity, dew point, air quality, etc). But what do I know, I only work on 290 million dollar aircraft, not in a parts store of a dealership.

Oh, and you guys down there need to stop listening to what John thinks he knows about me.... he, and you dont know anything about me or what Ive done or can do ;)

Have a nice day.

bryan00rt said:
I am fairly new to the group but i have been reading plenty of pages and threads trying to learn a new brand of vehicle i have never owned before. The one thing coming to mind is there are no outside sources dedicated to Engineering or Production of any REAL performance parts for some old Dodge R/T trucks. It would seem that anyone still attempting to "HONESTLY " support this group should be welcomed in today's time.
It also doesn't take long to see the same 2-3-4-individuals always critizing everyone else. No matter what you do they did it better attitudes although they are not much better than what i have read is out there already. In fact, What money have they ever taken out of their own wallets for any of you?
I begin to wonder if it is Bashing for Business, Personnal Vendetta, or just people trying to gain CONTROL over a group for whatever evil they have planned for you.
Some should begin to think about what certain people doing the most critizing really know themselves. One in particular claims to be a Mopar Guru ? Thats a pretty heavy "SELF PROCLAIMED "title with the likes of Mopars past Ronnie Sox, McCandless, Landy and others. Thats why i tried it. I was trying a super secret handshake defunct rocker adjustment for massive increases in power. Not only did i gain nothing but wasted my day, cost $50 for the dyno, and skinned a knuckle trying.
Then i read a post from " THE GURU" explaining how the Mopar oiling system works. I would expect a person selecting the GURU title would be the premier source of knowledge in this area. I was concerned and didn't want to oil starve my # 8 lifter as described would happen. Once the guys at the dyno session heard that one and the laughing stopped, I decided to open my FSM just to make sure they weren't just jealous of this guy. Guess what, the dyno guy knew more than the GURU !
Thats Two strikes GURU. So now do you really expect people to invest $400 in some Home Depot flat washers dropped into the clearance space of a lifter body and it's going to make them more magical gains as well ?
Oh Please, I have seen some things but the exploitation of a mass of inocent people that you are trying to do is criminal at best. At this point, I would not place much faith in the GURU. It would seem he needs some extra time behind that parts counter studying some FSM's and learn how a Mopar oiling system works before attempting to meet the challenges all of you have going on.

"Go Mopar"
Hey, I admitted I was wrong on the oiling system. Simple enough.

So you are telling me that you ran right out that day, and did a test ON THE DYNO to determine if I was full of shit or not?? hahahaha thats pretty desperate. I wonder if you have a different screen name you go by that most people would know you better as? hmmmm....

Flat washers in the lifters. Thats pretty good. Go ahead and do that and let me know how it works, Im sure youll like all the lil metal pieces in your motor.

And I am FAR from the one trying to control here... your lil clique of Mercedes boys is far more guilty of that... two of you attacking me, gee I feel honored.

Smell BS all you want boys. Ive known Mercedes longer than you guys have... and seen the results of his games. in fact two of his old cronies that had called me WAY worse names than you ever have or will, ended up getting screwed by Lord JM... and guess what, they are friends with me now... hmmm funny how time wounds all heels.

Ill just stick to posting what has worked for me and the guys up here. If you dont want to follow the advice, shut up and do it your own way and PROVE that your way is better, verses making unfounded claims ( funny.. you accuse me of that... ). Tell ya what, YOU take a stock heads/cam truck and get it into the 12's NA. THEN I will ask for your opinion... No I dont have the fastest, and I wont ever, I dont have the $$ to do it. But that doesnt mean that I havent built way more HP with less than most people, and have gone farther with less. Always have, always will :)

Back to your regular scheduled entertainment.

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Tanky said:
I stand corrected there, however, they were NOT made for Magnum 360s, thus entering the adapter plate design. SS took a 99 Dakota stock and made us headers from scratch.
What is it that you have against the so called "adapter plate design"??? do you know the purpose of it?

Tanky said:
If you say so Danno if you say so. Last I heard Dyno's have this thing called SAE calibration, which equals out the atmospheric conditions. Track times can't do that.

I don't need Aircraft knowledge to build my truck, I go to the experts, like John Mercedes, Glen Renzoni, etc. However, working on 45, 000lb of thrust Pratt and Whitney F117 engines, etc teaches you a little about performance differences when it comes to atmospheric conditions. Throw in my Bachelors degree in acft maintenance, my A&P license, all of which proves my point.

And if you want to claim to be the fastest trucks then so be it, but your not I assure you. Neither am I, but I know that already.
Funny how back to back dyno runs with no changes can vary by as much as 10 hp then isnt it?

If you are taking chassis dyno #'s as gospel, then there is no help for you. We racers have another name for that type... called dyno queens.

bryan00rt said:
The level of ignorance you are battling is from the type found in a cheap bar telling old war stories. They always end up killing the entire opposing Army and their rifle barrel was melting.
Look at the times Mr. GURU brags the most about. So What? There are faster times with less used to get them all over the net. He's to late to Brag but still tries to wipe all his retoric in all of your faces looking down at you. He is a NOTHING and any of you could be better.
Look at the magic parts testing program he does. Do any of you see where he has invested anything for you ? Here is a GURU that can only borrow parts to dyno or use others money and after it is all done does nothing to make things better. Oh, I forgot the LOEWS washer trick or was it HOME DEPOT? Probably wherever they were cheapest but charge you $200 for them.
I thought the Chevy Clubs were bad, You guys have your own issues in here with this guy. That's right Chevy for 11 years and Mr. GURU, your wrong on the name you keep bringing up to cover your ignorance. You better grab a Chevy FSM to take to the counter and study well. You are nowhere in the same league nor have the Intelligence to try.


Ok let me get this straight.

You have been on here how long? Owned an RT ( if you even do.. ) for how long? And you know that there are faster RT's out there with less done to them than mine?? HAHAHAH Ok that shows exactly what you DO know about these trucks.... nothing.

The rest of your post doesnt even rate a response... at this point the only thing you will get from me is silence. YOUR ignorance of this whole community is showing through in spades at this point.

And to quickly defend the lifters... why dont you start selling some with washers in them. I could use the competition.

Have a nice evening.

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


OK Ill go back to sleep now.


I guess the point we are TRYING to make, is that just because one particular vendor, who has a ton of "support" for lack of a better, less inflammitory word, says that this is the "newest greatest thing", doesnt mean that it is. I originally brought Jess's headers up to illustrate the point that we HAVE found that larger exh sizing is liked on these motors... ALOT. But that point was missed because *gasp* I was critisizing something that John M brought to market. How DARE I do such a thing... hes done so much for the Dakota RT crowd... Yeah he has, but then again so have I. Then they turn right around and tear into the lifters that Jess and I developed. Hell, you owned a set and were all gung ho to use em!
And as far as custom, Im not sure why you say that. There is NOTHING on Vader OR Barney, that you cant go out and buy.... nothing except the hoods that is ;) Every bit of both of those trucks are, I wont say readily, but available to the general public. Josh's setup is a lil more custom now, but it wasnt last year, Brads was pretty normal when he was running high to mid 11's. Jess's was also pretty reproducable. Ed and Mike C are about the only two that would be difficult to reproduce ( although Mikes is readily reproducable in the 11.49 setup... ) mainly because of the turbo setup on Eds, and Mikes Indy head setup. ( we wont talk about the chassis mods that Mike and Brad are into now... hahaha )

So in summation, yes, we have a hell of a good crowd up here, that are more than willing to share what we have learned, with a TON of track time. We have developed some stuff up here that we have then shared with other people, albiet on a limited basis, but its not like we are hoarding ( other than the hoods again.. hahaha ) the technology OR the knowledge.. you of all people know that we are more than willing to give advice and help anyone that asks. I know Jess gave up on it because he got tired of people acting like the guys in this thread. I guess Im just a glutton for punishment :jester: But I wont let a few people like these guys, keep me from pointing others in the right direction when it comes to mods.

BTW, as someone on Delphi just pointed out, the Spintech ( AKA GSM ) headers are still available through Rick Gindoy.... so there ARE options out there, not like everyone wants to believe that John is the only one doing anything for our trucks. You as well as I know thats a line of BS.

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Good ta see ya over here Jody!

Funny that no matter how much some things change.. how much they stay the same.

The even funnier part of this, is that you and Todd used to go round and round with me about all of this same shit back before half these guys even owned RT's... and look whos friends with who now ;)


Well the subject of the thread was lost long ago... trying to reclaim it might just be hopeless ;)

Chuck said:
I doubt they're like that on the inside. The builder does them a piece at a time and probably tigs them from the inside out. The rougher part of the weld is on the outside.

At least thats how I think its done.
Those are actually Mig'd.

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