Long Tube Headers

Discussion in '2015+ (S550) Mustang -General/Talk' started by I Bleed Ford Blue, Feb 6, 2018.

  1. Has anyone self installed a set of long tubes on their S550? Since I'm on vacation now until March 4th, I thought I would try to tackle the job myself. I just dropped over 1100 at LMR for a set of Stainless Power long tubes, they will be here by Monday.

    Also, does anyone know for sure if the exhaust port threads are 10mm x 1.5 or 10mm x 1.25? According to my research, the coyote engines started out in 2011 with the 1.25 threads and some time in the 11 production run ford switched to the 1.5 thread and all coyotes have had the 1.5 ever since. I want to make sure before I drive down to Summit racing and by the Stage 8 locking header bolts, they have both sizes in stock and the are the same price. I just want to get the right ones the first time.
  2. I installed mine in my garage on the floor. It was a project I won't forget anytime soon. My advise is, find a lift and an engine transverse bar somewhere you can use. There were no real issues with the installation other than the typical tight spaces and hard to reach bolts. You have to remove the motor mounts and the motor mount brackets and this is where the engine transverse bar comes into play. My Kook's long tubes came with Stage 8 hardware for the head flanges and for the collector to connection pipe joint. I used them on the collector but not on the head flanges. I was advised by others at a local speed shop to use the stock studs and fasteners which I did. I also used the new gaskets provided with the headers. With right at 10,000 miles on the installation, I feel I made the right decision, no problems, no leaks and at about 2,500 miles I checked the nuts that were easy to get to and they were still tight. The Stage 8 bolts are at home on my workbench, I can check the thread pitch or part number on them when I get home tonight.
  3. The part # that summit and stage 8 list for the header bolts is 8914C and that is for the 1.5 pitch, the 1.25 pitch is just 8914. Harbor freight sell an engine support bar and I live within walking distance from one.
  4. My packaging didn't have a part number but were marked 10mm-1.25x25 6pt DHH. I checked them with my thread pitch gauge and they are 1.25 thread pitch. That doesn't mean they sent me the right ones, I wish I would have tried one to see if they fit my 2016. Sorry I can't be more helpful.
    #4 Boone, Feb 8, 2018
    Last edited: Feb 8, 2018
  5. I guess I'll pull a stud and see what my car actually has.
  6. The headers were delivered today, the included bolts are 10 x 1.25. I pulled a stud out and it is 10 x 1.25 on both ends, the head side and the nut side. Tomorrow when i go down to summit, I'll let them know their info on the website is wrong.

    #6 I Bleed Ford Blue, Feb 12, 2018
    Last edited: Feb 12, 2018
  7. 10-4, sounds like a plan! I researched it also after talking to you and Summit was the only place I found that information. Everything else I found called for 1.25 thread pitch. It was hard to find much out there.
  8. Well I talked to the counter guy at summit and told him that my 17 had the 1.25 threads and so does someone else's 16 and more than likely all mustang coyotes have the same thing, everyone I talked to says the mustang coyotes all have the 1.25, they never heard of the 1.5 pitch. I don't know what the 1.5 fits, maybe the truck version? I also sent an e-mail to stage 8 to let them know, and I asked them if they would produce a set of locking nuts so we could reuse the factory studs.
    #8 I Bleed Ford Blue, Feb 13, 2018 at 1:00 PM
    Last edited: Feb 13, 2018 at 7:22 PM
  9. I got a reply from stage 8, here it is.

    Hello Mike,

    Updating the 5.0 Coyote exhaust bolt thread pitch has been a long running joke for some time now, for a lot of companies. Ford changed the thread pitch back and forth several times and we were all told the the final thread pitch would be M10-1.50. You can attest that's not the case. Many header companies put two sets of bolts in their headers so they cover both.

    We have Locking Nuts, we just don't make a header nut kit for the 5.0 but all you need to do is call and ask for them. We don't offer a nut kit because most people want to use bolts. Studs can still come loose even if they have a Locking Nut, the stud can still unscrew from the head. Using a bolt eliminates that.

    Thanks for the suggestions though I'm always keen to hear new ideas.

    Glenn Thompson
    Stage 8 Locking Fasteners

    After reading their reply, it now makes sense why they state on their site that all coyote owners should double check what thread they have before ordering.
    #9 I Bleed Ford Blue, Feb 13, 2018 at 7:23 PM
    Last edited: Feb 13, 2018 at 7:37 PM
  10. Great work! I had no idea that was the case. Thanks