When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So I bought the Flowtech 31106 headers for my Dart SHP 406 with the Dart SHP heads, and the bolts that were shipped with the Flowtech are too long. :WTF
So I'm looking for new bolts. I've read many reports of header bolts having to be retightened on occasion as some have a tendency to become loose after several heat/cool cycles.
In my view, the Stage 8 locking header bolts look like some of the best, but I was looking for real world examples and what others are using.
It looks like stage 8 has redesigned the "locking cam". I'm using them on my headers. I had to modify the locking device a little to make them match the position of the cam on the header with the bolt in it's final position. I put them on with anti seize then ran for several heat cycles and checking for tightness as the gasket compressed then installed the locking cam to keep the bolts in their final position.
So far they work fine and no blown manifold gaskets or loose bolts.
One thing I like about them is the allen wrench hole in the bolts so that you have two different options for tightening the bolts. I couldn't get a hex wrench on all of them to tighten.
I used these "pictured in above thread" when I installed my long tubes last May and drove all summer w/no problems. Other than modifying a couple locks.$45.
I used the stage 8 bolt kit in post #3 above and frankly I hated them. The bolts were difficult to install with the snap rings and the camber plates for each bolt did not fit around some tubes without modification. They were a royal pain to install. I used them on my Mustang GT with BBK shorty headers and I was chasing a header leak for about 1 year, loosening and removing the header gasket with these bolts was tedious. I finally found that the header flange was slightly warped and I used 2 felpro header gaskets with high temp RTV sealant between the 2 gaskets to solve the header leak and used the grade 8 bolts WITHOUT all the associated hardware. Tightened up the grade 8 bolts after a few head cycles without the hardware and guess what? Not one of the grade 8 bolts has even remotely loosened with over 1 year use now. Has anyone else discovered that the grade 8 bolts used alone will not loosen? Type of steel used? bizarre….
BTW-I used 2 header gaskets RTV'd together on my L-82 355 shorty headers as well to solve the header issue on that motor as well but used the regular headers bolts. Don't know if they will hold over time though...
I have the Flowtech 31106 headers. I installed them with the bolts provided without locks and I have not had any problems with them coming loose. I use that car mostly for autocross but I do drive it to and from the events.
I used the stage 8 bolt kit in post #3 above and frankly I hated them. The bolts were difficult to install with the snap rings and the camber plates for each bolt did not fit around some tubes without modification. They were a royal pain to install. I used them on my Mustang GT with BBK shorty headers and I was chasing a header leak for about 1 year, loosening and removing the header gasket with these bolts was tedious. I finally found that the header flange was slightly warped and I used 2 felpro header gaskets with high temp RTV sealant between the 2 gaskets to solve the header leak and used the grade 8 bolts WITHOUT all the associated hardware. Tightened up the grade 8 bolts after a few head cycles without the hardware and guess what? Not one of the grade 8 bolts has even remotely loosened with over 1 year use now. Has anyone else discovered that the grade 8 bolts used alone will not loosen? Type of steel used? bizarre….
BTW-I used 2 header gaskets RTV'd together on my L-82 355 shorty headers as well to solve the header issue on that motor as well but used the regular headers bolts. Don't know if they will hold over time though...
So, the initial problem was NOT caused by the Stage 8 bolts??? Interesting...... I have a set of Sanderson Block Huggers on my '74 350 and have Stage 8 bolts fitted. They were easy to fit and in three years I have never noticed an exhaust leak. And I fitted the Sanderson Headers WITHOUT ANY GASKETS as per their instructions. The Stage 8 bolts were of the type in the photo in Post #3.
First hand experience from Down Under, very happy with Sanderson and Stage 8.
So, the initial problem was NOT caused by the Stage 8 bolts??? Interesting...... I have a set of Sanderson Block Huggers on my '74 350 and have Stage 8 bolts fitted. They were easy to fit and in three years I have never noticed an exhaust leak. And I fitted the Sanderson Headers WITHOUT ANY GASKETS as per their instructions. The Stage 8 bolts were of the type in the photo in Post #3.
First hand experience from Down Under, very happy with Sanderson and Stage 8.
Regards from Down Under.
aussiejohn
The bolts were not the problem but the header flange warped. The bolts seem to be made of very high quality and seem to work as designed with the snap rings and camber plate but are tough to take on and off, if need be...
The Percy's vibe-lock bolts are awesome! I used those on my '69 RS Camaro when i built it 4 years ago along with the Percy's metal gaskets. Haven't had to touch them since. From now on that's the only bolts & gaskets i'll ever use for headers.
Don
The Percy's vibe-lock bolts are awesome! I used those on my '69 RS Camaro when i built it 4 years ago along with the Percy's metal gaskets. Haven't had to touch them since. From now on that's the only bolts & gaskets i'll ever use for headers.
Don
Those locking bolts look great….I may use them on the 78…Much better design than the Grade 8 bolt system...
Off the top of my head, I recall seeing something about header bolts marketed by Proform, that have some sort of tapered/serrated locking washer method. It looked interesting....
Off the top of my head, I recall seeing something about header bolts marketed by Proform, that have some sort of tapered/serrated locking washer method. It looked interesting....
Pro Form? that means " Hencho en China " use them if you like, I wouldn't!
The best locking header locking bolts are the ones that don't come loose on their own.
I use the 'short' black Mr Gasket bolts with lock washers. No leaks and snug on my paper Mr Gaskets for over 16 months. I have 3/8" flange Hedmann Hedders. I didn't do anything special with the gaskets either. Just torqued them down. I've heard that you should soak/dampen the gaskets in water to make them swell but I didn't trust myself to NOT turn them to mush from too much water soak.
The short header bolts with lock washers are about $10 for a set of 16 at local Auto parts store. At least, I hope the lock washers came with them... I may have cannibalized from a prior set of bolts.
The bolts were not the problem but the header flange warped. The bolts seem to be made of very high quality and seem to work as designed with the snap rings and camber plate but are tough to take on and off, if need be...
Did the flange warp in one of the two areas between the exhaust ports?
I ask this as I was chasing valve train noise and thought it was exhaust leak. I resorted to removal of the headers and hack sawing the flanges so that the single flange on each header became three individual flanges. I cut about mid-way between 7-5, 3-1, 8-6 and 5-3.
Did the flange warp in one of the two areas between the exhaust ports?
I ask this as I was chasing valve train noise and thought it was exhaust leak. I resorted to removal of the headers and hack sawing the flanges so that the single flange on each header became three individual flanges. I cut about mid-way between 7-5, 3-1, 8-6 and 5-3.
Be honest I don't recall.Double gaskets solved the problem-no exhaust leaks.
Best header locking bolts?
