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  1. #1
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    6.1 exhaust manifolds on non eagle with RT midpipe

    Looking to buy some 6.1 exhaust manifolds for my 5.7 and have a couple questions and a forum search hasn't gotten me any solid answers.

    1) How well do the ports mate to the non eagle heads?
    2) From what I have found you can drill the manifold & gasket and retain the egr.
    3) I would like to adapt my existing awd RT midpipe to them. I was thinking of cutting & welding 6.1 flanges to it. Anybody know how far off they are from the 5.7 pipes? Is it possible or way too much fab to be worth it? I have an SLP cat back but midpipe is still stock.
    05 Magnum RT AWD
    56 Plymouth Belvedere - Twin Turbo EFI 354 (early) Hemi
    72 Chevelle 4DR - EFI 396 T56 6spd



  2. #2
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    I think the 6.1 are 3" and the 5.7 are 2.5"
    I just bought some shorty headers. With big valve heads, cam and eagle intake, I make about 400 RWHP so perf is similar to the Scat Pack.
    The shortys are just so much simpler and you do not lose that much.
    2005 Dodge Magnum RT.
    12/2016 - Inertia big valve heads, Eagle intake, non-MDS lifters, Spartan Plus cam, Shorty headers. 390 RWHP, 390 RWTQ. (Work by Inertia)
    01/2017 - Bilstein shocks, SLP 25% underdrive pulley. s/b 400 RWHP, 400 RWTQ now. (Work by me)
    10/2017 - Replaced engine mounts with 392SRT manual transmission, added police oil cooler, additional PS and Trans coolers, Mishimoto radiator. (Work by me)
    10/2017 - Replaced Torque Converter with FTI 3,000RPM, Installed 3.73:1 Getrag kit. (Work by True Street Motorsports)
    11/2017 - Wilwood brakes with 15" front brakes. (Work by me)

  3. #3
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    Ok so I would have to weld in a 3" - 2.5" transition. Not a lot of room for that before the cats.

  4. #4
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    You also have issues because the O2 mount in different spots.
    The 6.1 in mid while 5.7 is in exhaust manifold.

    Sent from my SM-G925V using Scat Pack Forums mobile app
    2008 Magnum BB R/T Hemi Registry # 1584 PPP Stage 2 Cam, JBA Shorty Headers, JBA High Flow cats, Heartthrob Exhaust, Eagle Intake, LMI Intake, MTCM, Blue Tops, ProTorque Converter, SRT Rear, Techo Strut Brace, lowered, Tuned by Diablotoona SOLD--2005 Mineral Gray AWD Hemi Registry # 1154

    Quote Originally Posted by Hemissary View Post
    For the work being performed, length is far more important than diameter :^)

  5. #5
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    I went thru this on my 2010 Challenger. Parts for sale link

    1) 6.1 shorties fit just fine.



    2) Get MOPAR Gaskets and Header bolts.


    3) Add a spacer to the 5.7 dip stickbolt and use your 5.7 dipstick.


    4) I had a set 5.7 Corsa Cat back and just took the mids to the muffler shop and had swag the end of mid pipe to fit OVER the Corsa pipe.

    5) Get O2 sensor with longer leads. I have spare set.


    2017 Granite Crystal Scat Pack

  6. #6
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    So hemi_57 are you saying the manifold end of the 5.7 midpipe will bolt too the 6.1 manifolds? I have O2 bungs and can weld them onto my mid pipes and can solder extensions to the O2 wires. Not concerned about that at all. That's easy to fix. I am mainly concerned about how to mate my midpipe to the manifolds.

  7. #7
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    Quote Originally Posted by 56Hemi View Post
    So hemi_57 are you saying the manifold end of the 5.7 midpipe will bolt too the 6.1 manifolds? I have O2 bungs and can weld them onto my mid pipes and can solder extensions to the O2 wires. Not concerned about that at all. That's easy to fix. I am mainly concerned about how to mate my midpipe to the manifolds.
    No... You need 6.1 mids.

    I had 5.7 Corsa cat back. So, had to swage the 6.1 mids to fit OVER the Corsa pipe. 6.1 pipe 2.75 and 5.7 is 2.5.

    I wouldn't extend the o2 sensors via soldering. I read a Bosch bulletin about extending o2 leads. Make me an offer on the o2 's if they fit.

    Sent via Tapatalk

  8. #8
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    The extensions may be needed because 5.7 O2 is in manifold, and 6.1 is in mid, so its like 4" farther and some cant reach that far

    Sent from my SM-G925V using Scat Pack Forums mobile app

  9. #9
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    Unless you like Check Engine lights, don't extend the 02 harness by soldering. The extensions aren't that much and they'll keep the CEL happy lol

    Sent from my XT1650 using Tapatalk

  10. #10
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    Hemi_57, Can you take some measurements off your 6.1 Manifolds for me? Would really appreciate because I measured my 5.7 midpipe and yes the outlets are 2.5" but the inlet or manifold mating end is actually 3" ID. So I am thinking it could be possible to adapt it. Just a little cutting, fabricating & welding needed.

    I'd like to know:
    1) Flange bolt spacing center to center
    2) ID of the manifold flange opening
    3) OD at the base of the cone on the manifold that fits into the midepipe flange.

    I want to compare these to my 5.7 stuff.

    Oh & BTW is Hemi_57 for 5.7 Hemi or do you have a 57 Mopar with a Hemi? Just curious as I am also building a 56 Plymouth with an early 354 Hemi.

  11. #11
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    OP I have 6.1 shorties and JBA catless mids fs depending on your location

  12. #12
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    Quote Originally Posted by 56Hemi View Post
    Hemi_57, Can you take some measurements off your 6.1 Manifolds for me? Would really appreciate because I measured my 5.7 midpipe and yes the outlets are 2.5" but the inlet or manifold mating end is actually 3" ID. So I am thinking it could be possible to adapt it. Just a little cutting, fabricating & welding needed.

    I'd like to know:
    1) Flange bolt spacing center to center
    2) ID of the manifold flange opening
    3) OD at the base of the cone on the manifold that fits into the midepipe flange.

    I want to compare these to my 5.7 stuff.

    Oh & BTW is Hemi_57 for 5.7 Hemi or do you have a 57 Mopar with a Hemi? Just curious as I am also building a 56 Plymouth with an early 354 Hemi.
    I would love to get the info for you but all I have left are 6.1 shorties and mids. But, I do have some photo's that might
    show you what you want.

    Header differences:
    1) The 5.7 flanges are almost 90° out from the 6.1.
    2) The 02 sensors are in different locations, short sensor lead on the 5.7.



    Cats/Mids:
    1) You can see the physical size difference.
    2) The flange orientation is much more obvious.
    3) Rear O2 sensors locations are also more obvious.



    5.7 Corsa Sport to Magna Flo HF cats.
    You see the difference in the OD of the Manga Flow & Mopar mids compared to the ID of the Coras cat back.
    You can also see the Magna Flow pipe is actually necked down to fit inside the cat back pipe. I wasn't about to spent $1,200
    for a new cat back system. The muffler shop was about expand the Magna flow pipe to fit OVER the Corsa pipe and not split it.



    And Yes the 57 is for the engine size of my Challenger.
    Last edited by hemi_57; 07-15-2018 at 10:20 PM.

  13. #13
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    And keep in mind Jeep SRT 6.1 manifolds are a little different that LX/LC 6.1 manifolds. i.e Jeep SRT manifolds will not fit on SRT LX/LC midpipes.

  14. #14
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    Looking at the pics above and comparing them to my mid pipe I don't see why I can't adapt mine to fit the 6.1 headers. I know I'll be leaving some performance on the table but that's easy to upgrade later. The exhaust manifolds not so much once the engine is back in the car. Much easier while the engine is on the stand. Plus how much difference could going down to 2.5" a few feet later really make. The cat is the main restriction there. I've been trying to upload some pics of my mid pipe but it fails every time. No idea why. But basically my RT midpipe (which being a 2005 is slightly different than the one above) Has a 3" pipe into the cat. The only difference I can see from the 6.1 is the flange bolt spacing (which is why I wanted that measurement), the orientation of the flange, and the length of the pipe before the cat. Since the RT midpipe is longer because of the shorter manifolds I don't see why I couldn't just cut the pipe to the proper length and weld a 6.1 flange on. I have the welder & the skills.

    Wish I could upload some pics....

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