FYI FORD MustangSteve's Ford Mustang Forum / Header bolts

**Posted by 1fststang** 1/01/2019 6:12 PM

Will be installing an engine in my 67 Fastback soon and thinking about using some locking header bolts like stage eight. Anybody using these and have they worked up to the hype?

I have a set of FPA headers with the 3/8" thick header flange and using AFR 205 heads using the outside set of header holes in the heads.

Looks like the inside header holes are threaded about 1"' inch in to the head but the outside bolts are only threaded 1/2". Feel like I'm stuck between header bolt sizes. A 1" bolt is to long and will bottom out and the 3/4" will work but doesn't seem to engage enough threads for my liking(maybe .25").

**Posted by Bentworker** 1/01/2019 7:35 PM

I did not use the stage 8 bolts for one reason.

They look like a pain to install.

That being said I’m sure they would work great.

I have 1” ARP 5/16” head 3/8-16 bolts with Nord-Lock washers. Nord-Lock washers are kind of a trip, they have two half’s that are serrated on one side and have ramped teeth on the other. When you try to turn a fastener counterclockwise that has a Nord-Lock on it the ramped teeth slip against each other, making the washer “thicker” and causing the serrations to bite in even harder. Basically binds it up. You can get them from lots of sources including McMaster-Carr.

Just another option if you are looking.

Last edited by Bentworker (1/01/2019 8:09 PM)

**Posted by TKOPerformance** 1/01/2019 8:01 PM

I've used them before. They are a bit of a PITA to install. One thing they do not tell you in the instruction is to install them WITHOUT the locks. Run the engine up to temperature and let it cool, THEN install the locks. If you don't do it that way you will be taking the locks right back off to tighten the bolts once they've heat cycled and you start to hear the ticking of a leak or two. They do work otherwise, but installing and removing the locks is not what I would call enjoyable.

Honestly, on an early Mustang the access to the bolts is good. I can check/retorque mine in about 10 minutes. I just don't see the need for exotica in this area when simple maintenance works just fine, and isn't a big deal.

On the bolts the rule of thumb is that the threads need to engage the thickness of the fastener to allow it to be properly torqued. You can always trim 1/8" off the 1" bolts if needed. A grinder or sanded can be used, as well as a cutoff wheel, etc. I would advise threading a nut onto the bolt prior to cutting it down. When you take the nut off it will clean the starting thread and make installing the cut down bolts easy.

**Posted by 1fststang** 1/01/2019 8:36 PM

Thanks for the feedback

Yeah I have shortened bolts before and having the nut on before is a wise move.

I'm afraid the 3/4" bolts just won't have enough threads engaged so I may need to do like you said and shorten the 1" bolts. I guess if I could find some good washers about 1/8" thick that may work as well.

**Posted by Bentworker** 1/01/2019 9:16 PM

The 3/8” Nord-Lock washers https://www.mcmaster.com/91074A131 are right at .100” thick.

Last edited by Bentworker (1/01/2019 9:16 PM)

**Posted by Rudi** 1/02/2019 10:22 AM

I use stainless steel socket head cap screws, no washers with anti seize in aluminum heads. Header flange thickness will determine the correct length. A lathe makes short work of getting them to the right length. Easier to get an Allen wrench in there than a socket.
One thing I must say as to Prothane engine mounts, since I installed them the header bolts they have not needed re torquing , you may get the same results from solid mounts.

**Posted by DC** 1/02/2019 10:32 AM

Rudi has the right idea, I have done the same thing and always remember to retorque after the first 6 or so heat cycles. The allen heads make that a lot easier.

**Posted by MS** 1/02/2019 2:54 PM

This is what I do. I use 1" long bolts with a thick, grade 8 lock washer. Anti-seize compound on aluminum heads. I have NEVER had a header bolt work loose. WAY lots of Mustangs and driven many, many miles. I find the need for anything exotic to be a waste of time, but those ribbed washers do look pretty cool.

Tighten the bolts properly in the first place and they will not come loose. Like any other fastener, there must be a little stretch induced in the bolt for it to do its job. Wimp out, and you have loose, wimpy bolts.

T least equally important: Be sure you have a crossover tube between the pipes to stabilize the exhaust system, making it act as if it is a one piece system. That keeps the pipes from swaying side to side and ruining the header gaskets at the heads. The headers have a lot of leverage if they can move. They will crush the gaskets and then you have loose bolts.

Stage 8 bolts.... Laughable. I bought a set once many years ago to give them a try. They are for Chevys. First, it is nearly impossible to get the lock washer piece to even GO ON the bolt due to the Ford bolt pattern being closer to the header tube. Second, the lock washer pieces fit LOOSE on the header bolt. Probably can only hear them vibrating in my own crazy mind, but there will be 16 little constant rattles going on when the engine is running, except for the ones you did not install because they would not fit. I gave them to a guy at work that had a Bowtie 350 in his 32 Ford. I think he threw them in the trash.

Those gadgets come under my rule of GIZMOS.
You should not install (BUY) something just because someone put it on the market. You should only install something that makes an improvement over the parts being replaced.
Thank GOD there have not been any posts yet on which adhesive fender portholes work best.

**Posted by Raymond_B** 1/02/2019 4:05 PM

Really good point on the primary size and room for the bolt. The headers on my 351w have 2 or 3 ports that I had to use special ARP small head bolts on because nothing else would fit. I really wanted to use the socket head bolts, but they hit the header tube.

**Posted by rpm** 1/02/2019 6:29 PM

Raymond_B wrote:
The headers on my 351w have 2 or 3 ports that I had to use special ARP small head bolts

Which ones Raymond? Do you have a part number?

**Posted by Raymond_B** 1/02/2019 7:18 PM

I ended up using ARP 100-1401, I about passed out when I saw the price though so be ready! My truck has Kooks stainless 1 3/4 primary header. Fit like a dream, but there's some tubes that are a royal PITA to get tight.

https://www.jegs.com/i/ARP/070/100-1401/10002/-1

1st pic is the 100-1404 IIRC and you can see on the 2nd stud I could not even get the nut on, 2nd pic is the 1401, hard to see well, but those save a ton of space. I probably could have gotten away cheaper with bolts, but I really liked using studs makes hanging the headers sooooo easy!

Last edited by Raymond_B (1/02/2019 7:20 PM)

**Posted by rpm** 1/02/2019 8:25 PM

Thanks Raymond. Ya, I'm sure it's all those 12 point nuts that increases the price. But they sure are sexy, and allow a smaller socket. You can't go wrong with ARP.

**Posted by DC** 1/03/2019 12:41 PM

Yeah I bought a set of those funny stage eight things once and finally found a use for them when they went to celebrate 100 day in my Grandson's first grade class.

**Posted by TKOPerformance** 1/03/2019 4:27 PM

I wonder if you started that second nut as the first fastener before the header was all the way up tight to the head if you could get the nut on it. It looks like one of those header bolts where the clearance gets worse the farther off the flange you are because the pipe turns right in front of it. Stuff like that makes me question whether or not the companies that build the headers ever actually try to install them.

**Posted by Raymond_B** 1/03/2019 5:23 PM

TKOPerformance wrote:
I wonder if you started that second nut as the first fastener before the header was all the way up tight to the head if you could get the nut on it. It looks like one of those header bolts where the clearance gets worse the farther off the flange you are because the pipe turns right in front of it. Stuff like that makes me question whether or not the companies that build the headers ever actually try to install them.

I sold the 1st set of ARPs to recoup a bit to pay for the crazy expensive 2nd set I did mess with it for a day and quickly convinced myself that it was worth it for the extra $$$. In Kooks defense they included a bolt set that would work, but I really like using studs. Just makes everything easier IMHO.

**Posted by Ron68** 1/03/2019 11:33 PM

So MS, I was looking at a nice set of portholes that remind me of the old Buick my dad used to drive. What type of adhesive did you use on yours?

**Posted by Nos681** 1/05/2019 10:13 PM

I believe I still have my “locks” in the old tool box. Definitely had clearance issues with tri-y and hooker 6901’s.