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Thread: New Exhaust, Old Studs

  1. #1
    Member mwesten's Avatar
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    New Exhaust, Old Studs

    All - as I slowly work 10187 back to a safely running car (eg. fuel, brakes, cooling, etc), Im starting to plan for other stuff like exhaust. I havent began disassembling yet, but wondering, in the event the new exhaust headers have 4 mounting holes per exhaust port, would it be possible/ok to switch to unused mounting holes in the event I run into problematic old studs? Obviously Ill try to get old broken studs out, but considering stock setup utilized 2 studs per port it would seem acceptable to do the same where necessary. Thoughts?
    Last edited by mwesten; 08-27-2023 at 07:25 PM.

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    Myself I don't see anything wrong with it. But also I would check and chase the threads to make sure there clean.




    Dave B.

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    If you are patient and use an acetylene torch to heat things up you should be able to undo all of the nuts without breaking anything. The way I do it, I heat the nut up to cherry red, let it cool and then heat it up to cherry again. Before it cools I use a wrench and go back-and-forth till I feel it is loose enough to come off. Rarely do I break anything but sometimes the threads do get messed up. The exhaust can wait till you can get other things going. You have more than enough just to get the fuel, cooling, and brake systems going.
    David Teitelbaum

  4. #4
    Member Dickey's Avatar
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    Quote Originally Posted by mwesten View Post
    All - as I slowly work 10187 back to a safely running car (eg. fuel, brakes, cooling, etc), Im starting to plan for other stuff like exhaust. I havent began disassembling yet, but wondering, in the event the new exhaust headers have 4 mounting holes per exhaust port, would it be possible/ok to switch to unused mounting holes in the event I run into problematic old studs? Obviously Ill try to get old broken studs out, but considering stock setup utilized 2 studs per port it would seem acceptable to do the same where necessary. Thoughts?
    If you're insistent on keeping factory DMC manifolds, I recommend renting/purchasing an induction heater for the studs.


    Outside of that, when I ran into this exact problem because two of the exhaust studs had completely dissolved flush with the head on mine I was able to use Eagle Premier manifolds instead which use different bosses compared to the DMC ones. They look a bit nicer as well:


  5. #5
    DMC Midwest - 815.459.6439 DMCMW Dave's Avatar
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    I believe all the aftermarket header kits have all 4 holes just for this in mind. My personal preference is to actually use all 4 though.

    CAUTION if you drill them out, overdrilling the upper ones will go into the cam area and the lower ones will go into the water jacket. Neither is a particularly happy occurrence.
    Dave S
    DMC Midwest - retired but helping
    Greenville SC

  6. #6
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    Quote Originally Posted by DMCMW Dave View Post
    I believe all the aftermarket header kits have all 4 holes just for this in mind. My personal preference is to actually use all 4 though.

    CAUTION if you drill them out, overdrilling the upper ones will go into the cam area and the lower ones will go into the water jacket. Neither is a particularly happy occurrence.
    I rarely have a shop work on my car but for an exhaust leak that involved taking off the manifold I found a local shop that had a reputation for not breaking studs. I bought the exhaust kit of studs, nuts, gaskets and had them take the old studs out (didn't break any), shaved the manifold flat and replaced it for $400. It was worth it to me as once you strip the stud you are in for hours of tedious work.

  7. #7
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    Quote Originally Posted by Dickey View Post
    If you're insistent on keeping factory DMC manifolds, I recommend renting/purchasing an induction heater for the studs.


    Outside of that, when I ran into this exact problem because two of the exhaust studs had completely dissolved flush with the head on mine I was able to use Eagle Premier manifolds instead which use different bosses compared to the DMC ones. They look a bit nicer as well:

    Do you have a pic with these installed?

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    Quote Originally Posted by David T View Post
    If you are patient and use an acetylene torch to heat things up you should be able to undo all of the nuts without breaking anything. The way I do it, I heat the nut up to cherry red, let it cool and then heat it up to cherry again. Before it cools I use a wrench and go back-and-forth till I feel it is loose enough to come off. Rarely do I break anything but sometimes the threads do get messed up. The exhaust can wait till you can get other things going. You have more than enough just to get the fuel, cooling, and brake systems going.
    Hi David,

    Without a torch would repeated soaking and gradually trying to get it to move stand a chance ?

    Can you achieve the temp required with one of the handheld gas bottle torches ?

  9. #9
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    Quote Originally Posted by er1c View Post
    Hi David,

    Without a torch would repeated soaking and gradually trying to get it to move stand a chance ?

    Can you achieve the temp required with one of the handheld gas bottle torches ?
    Once I removed a couple studs with a car battery and jumper cables. You ground the engine and hook the cable to the stud. The stud is locked by corrosion, so it gets red hot right where you need it. Did that a couple times and then turned it out with a vise grip. It?s hard on the battery though.

  10. #10
    Senior Member Bitsyncmaster's Avatar
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    Quote Originally Posted by Helirich View Post
    Once I removed a couple studs with a car battery and jumper cables. You ground the engine and hook the cable to the stud. The stud is locked by corrosion, so it gets red hot right where you need it. Did that a couple times and then turned it out with a vise grip. It?s hard on the battery though.
    That is a good idea. I have a spot welder that I could attach battery cables to which would probably also work. Also would not create a big spark.
    Dave M vin 03572
    http://dm-eng.weebly.com/

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