OBX Maximizer Long Tube Headers – Part# MH12541 (910-3403-2) Install Thread

[Hellcat Hauler]

Installation of OBX Maximizer Long Tube Headers – Part# MH12541 (910-3403-2)
I bought them on wal mart dot com for $281 plus $119 shipping plus $24 tax = $424.00
I took a gamble with china knockoffs and saved over $2,200 from the big names.
Upon arrival, very happy, very minimal effort to be 100% satisfied. I would buy these again.


I did port and sand out the inner welds on the ports.

 

[Hellcat Hauler]

Let’s start the install.
NOTE*** Use anti-seize on O2 sensor threads, bolt threads, spark plug threads when reinstalling.
NOTE*** I did NOT need to remove wires/shields/plugs because of my header design.
You can do this on a lift or with a jack on the ground, most of the work is done in the fender well.
Disconnect positive and negative battery terminals.
Loosen all front lug nuts with truck on the ground.
Lift truck, support with jack stands if working on ground.
Remove both front wheels or do one side at a time.
Remove all four O2 sensors, 7/8” wrench.
Remove all 6 exhaust manifold to cat pipe bolts, use a 11/16” wrench on back square nut or it spins.



Remove both front fender liners, 8mm bolt heads.


-Passenger side
Remove (3) 1/2” nuts and remove the spark plug wire boot metal heat shield.
Remove (10) 1/2” bolts, remove right side manifold through fenderwell. Remove all gasket pieces.


Clean head gasket surface with 2” 3M White roloc bristle. Blow clean with compressed air.


Wipe down head/header gasket surfaces with brake clean/lacquer/acetone.


Header is installed from under truck, install gasket, install all bolts by hand. I used Stage 8 bolts.


I got metal gaskets from JTSV


Tighten bolts from center outward on flanges, tool snug, then torque to 22ft lbs same pattern.
Install Stage 8 bolt locks now.

Install O2 sensor in header.

****Modifications needed to passenger side are in next post****

 

[Hellcat Hauler]

These are the modifications needed on the passenger side.

The heater hoses were too close to the header back by the firewall.
I removed the two bolts holding the AC drier bracket to the pcm bracket.
I installed two spacers between the two brackets and pulled it as far forward as possible.


This gave room to run the two heater hoses between the brackets and away from the header.




I added a couple zip-ties, but did still use the battery tray bracket support.

The abs plug is very close to the one header pipe when installed on the inside of the fender well.
I relocated it to the opposite side in the fender well, this pulls the wire from having slack.


This has sufficient clearance from the tire.

That was it, the header fits perfect and has good clearance.

 

[Hellcat Hauler]

-Drivers side
Remove 1/2" bolt from steering shaft and separate halves.
Remove (3) 1/2” nuts and remove the spark plug wire boot metal heat shield.
Remove (10) 1/2” bolts, remove left side manifold from under truck. Remove all gasket pieces.
You will need to unclip the starter wire from the kmember to gain clearance for the manifold to slide out.
Block/Bellhousing will need to be clearanced, it will barely touch when you rock header after it is bolted tight, grind the corner at angle.




Install new positive battery cable/switch wire from starter to battery, much harder with header in.
This process will be broken down on the next post.

Clean head gasket surface with 2” 3M White roloc bristle. Blow clean with compressed air.

Wipe down head/header gasket surfaces with brake clean/lacquer/acetone.
Header is installed from under truck, install gasket, install all bolts by hand.
Tighten bolts from center outward on flanges, tool snug, then torque to 22ft lbs same pattern.
Install Stage 8 header bolt locks.
Re-connect steering shaft, use lock-tite on bolt.
Install O2 sensor in header.

 

[Hellcat Hauler]

Starter wiring relocation and new parts needed on drivers side.
***Do this before bolting new header on.***

***Make sure NEGATIVE battery terminal stays disconnected during re-wire***

NAPA Parts
60” red 4 gauge cable (#781163)


1”x36” Thermo sleeve (#7353967)


Positive Battery Terminal (#92608821)


24” red 4 gauge cable (#781157)


The diagrams show factory starter wiring vs what we are creating to stay away from the header and heat.



As you can see, we are removing the following;
-factory positive battery terminal
-factory wire heat shielding
-factory positive cable that runs from battery to starter
-factory positive cable that runs from battery to fuse distribution box, we cut this off at the fuse box terminal end because it is crimped to the terminal with the alternator wire. Wrap nicely with electrical tape.

We run the starter solenoid wire and the 60" cable through the new heat shielding. You can attach everything with zip-ties, stainless zip-ties, or heat shink. You want that shielding close to the starter terminals, but you do not want it touching the positive terminal on the starter because it is a metal material. It is live power all the time when the battery is hooked up. We route this through the opening between the block and motor mount bracket. We attach at the front of the block with a P clamp and a 3/8 thread bolt. I zip tied to the power steering pump metal piping as well. I also attached to the fuse block/alternator wire with zip-ties.
Bolt your new + terminal on the battery. Connect the 60" and 24" cables to the new + battery terminal, on separate large studs. Connect any other eyelet wires that run to your + terminal on the small stud. Now connect the other end of the 24" cable to the fuse box terminal stud, it is where you cut the original wire off at the fuse box. Tuck everything neatly and zip-tie everything organized. I loomed and taped all my wires, even the ones in the heat shield.
See next post for finished wiring pics.

 

[Hellcat Hauler]

Now you need to install the mids, rear O2 sensors, tighten clamps, and negative battery terminal.
Not a terrible job by any means. I rate the headers a 9.5, all headers require some mods to fit.
I would highly recommend the Maximizer brand, quality was great, fit was great.
Plan on porting the inner welds if you want maximum HP. I would laugh at anyone who calls these china junk or low quality. Maybe the materials are not the same, maybe they will get little surface rust spots, who cares. $424 and I do not drive the truck as a daily or in any bad weather. Any question, just ask!

Mopar Performance Baby! bǎo bèi 宝贝

 

[Wifey]

Great thread!! Good information!

NOTE: I like your placeholders! Ho proofing lol

 

[Wifey]

Okay your HIRED!!! fabulous write up, clean work, thanks for sharing!!

 

[VIPR PWR]

Nice info on the install ! Seems it’s a reasonably easy install .. the toughest part appears to be the new wiring ,routing from the starter . Do you think there are other wire routing directions that could be utilized to make access if needed later easier ? Maybe even a relocated battery to the inside of the rear fender well , which I think Justin @ JMB Performance made a kit for !
there is no doubt the price is great and even if they don’t hold up over time would still be cheaper to buy or have a second set and would still save a ton of cash hahahaha !

 

[VIPR PWR]

This is the Battery relocation kit from JMB Performance I mentioned above ;
https://jmbperformance.com/product/srt-10-rear-mount-battery-package/

 

[Hellcat Hauler]

Yes, I had seen it before.
I am not drag racing my truck so I would never relocate my battery. That would make it a pain to change out a new battery in a hurry. (of coarse it would be raining and it looks like you have to lay on your back for this setup lol)

But, it would still be easy to do the rewire basically the same way. The minor problem is that you need to get all the small eyelets over to that fuse box stud as well, so that will require a few shrink butt connectors, shrink end eyelets, a couple feet of wire added to each, and looming them up.

 

[VIPR PWR]

Yes, I had seen it before.
I am not drag racing my truck so I would never relocate my battery. That would make it a pain to change out a new battery in a hurry. (of coarse it would be raining and it looks like you have to lay on your back for this setup lol)

But, it would still be easy to do the rewire basically the same way. The minor problem is that you need to get all the small eyelets over to that fuse box stud as well, so that will require a few shrink butt connectors, shrink end eyelets, a couple feet of wire added to each, and looming them up.

View attachment 65868

Ok .. got you ! The secondary purpose I asked was I like a less cluttered engine compartment and moving the battery would make a big difference to me .

 

[Hellcat Hauler]

https://youtube.com/shorts/7NnExrm1L60?si=bIoEQv1JspT4I3ob

 

[Hellcat Hauler]

 

[VIPR PWR]

https://youtube.com/shorts/7NnExrm1L60?si=bIoEQv1JspT4I3ob

Excellent .. Sounds strong !

definitely no complaints about the parts and Job well done !

 

[Wifey]

Sounds GOOD!!

 

[Wifey]

Your Hellcat sounds great too!!

 

[Hellcat Hauler]

You snooze, you lose!

 

[Wifey]

You snooze, you lose!
View attachment 65902

Zonnnnnkkkk!!!

they didn't indicate that was sale pricing you got but it did seem to good to be true!

Good for you and not so much for the snoozers!

 

[VIPR PWR]

You snooze, you lose!
View attachment 65902

I’m out ! Damn ! Looks more like some did a price goof when you bought your hahaha !