63dartman
Well-Known Member
I've searched and searched and can't find any 5/16-18 3/4" header bolts that have a head on them for a 5/16" wrench. ARP makes them in 3/8 but that's it. Any ideas on where to get them?
5/16 wrenching header bolts
- Thread starter 63dartman
- Start date
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Xstream_1
Well-Known Member
Have you looked at ARP #144-1102 for the black oxide and 444-1102 for the stainless?
Xstream_1
Well-Known Member
You the man!!!! I have small head bolts on my small block. Great for the tight spaces.
63dartman
Well-Known Member
for some reason those heads look bigger than a 5/16 wrench....maybe a 7/16 wrench? I went to the arp website and they don't list the wrenching size for the mopar bolts. They do have a universal bolt kit with 5/16 wrenching but only in the 3/8 thread size. I sent an email to ARP requesting the info. Thanks for the help.
Xstream_1
Well-Known Member
I believe you are correct. They may have a 3/8 head, I'll call my vendor and find out for you.
63dartman
Well-Known Member
I'm using 3/8 head bolts now and two of the bolts on both sides are extremely hard to get any torque on to get them tight enough. Thanks again for taking the time to help out.
Xstream_1
Well-Known Member
Have you thought about allen head bolts?
63dartman,
Try running those bolts all the way down snug first, then tighten the others. They are the #2 and #5 bolts counting from either end 1-6 correct? Those two bolts are always a pain.
Try running those bolts all the way down snug first, then tighten the others. They are the #2 and #5 bolts counting from either end 1-6 correct? Those two bolts are always a pain.
beware using just any allen socket head allen screws. They are set screws and made of extremely hard material. Loads of anti-sieze on the threads so if they do break they may screw back out. Even the stainless ones are easier to drill out than the standard hardware store set screws.
63dartman
Well-Known Member
I really don't want to use the allens, and I do believe it's the 2 and 5 bolts but that's coupled with the spitfire headers and makes it twice as bad.
fishy68
Tyr Fryr's Inc.
Have you tried angle wrenches? I have a set of Snap-on angle wrenches and with them I can torque them all down fine. There are other less expensive sets also like Mac and Matco.
63dartman
Well-Known Member
Fishy, thanks for the tip, I never thought about reverse engineering my problem. Those are sorta like the ignition wrenches only larger right? I'd still like to find those damn bolts.....They make em in 3/8 for all the damn chevy and ford guys. Just got confirmation from arp that the bolts above are in fact 3/8 wrench size.
If and when you do find a 3/8 bolt with a 5/16 head I wanna see that too. Never have before. Standard for 3/8 dia. is 9/16 hex. I have some GM header bolts from and ol ElMeano I had that have 7/16 hex heads. Thats 2 sizes under standard. But thinking about it... a 5/16 head smaller than the 3/8 shank wouldn't hold anything.
dgc333
Well-Known Member
The Hedman headers I have came with the 5/16-18 bolts with 3/8" hex. There are only a couple of bolts that I need to use an open end wrench on. I find that with the Hedmans any way that if I start those that are real close to the tube and hard to get at I start those first nd keep the header away from the head and bring the flange in with the bolt then do the others.
63dartman
Well-Known Member
Redfish, ARP sells the 3/8" thread size with a 5/16" head size. If you look at the pics of the 3/8" head above you can see that it widens at the bottom of the head to increase the strength. I'm looking for 5/16" thread size with a 5/16" head size. Can't seem to find that one since it's not a chevy or ford bolt. Dust, thanks for the help, I will call and see if they will sell them or give up the source.
fishy68
Tyr Fryr's Inc.
Fishy, thanks for the tip, I never thought about reverse engineering my problem. Those are sorta like the ignition wrenches only larger right? I'd still like to find those damn bolts.....They make em in 3/8 for all the damn chevy and ford guys. Just got confirmation from arp that the bolts above are in fact 3/8 wrench size.
Yeah Dartman that's them. The smaller head bolt would be easier to work with. If you do find them let us know where. I wouldn't mind a set for mine. I allways install them like DGC said but even then it's not the easiest.
edbux
Well-Known Member
Try looking online at McMaster-Carr. They're an industrial supply place and have a huge selection of hardware....and just about anything else you could need.
63dartman
Well-Known Member
Good idea edbux, I forgot about that place. I'll give it a shot. Thanks
63dartman
Well-Known Member
would this be the 5/16" wrenching? Looks like edbux get's the :drinkers: thanks a bunch. Best part is they are available in 3/4, 7/8 and larger lengths. The 7/8 length are $8.79 for a pack of 50 grade 8 or better.
grade 8 or better.
dgc333
Well-Known Member
Those won't work on all the bolts. You need to use the box end of a combo wrench or a 12 point socket and there is not enough room for either.
Had the same issues and the standard size would 9/16 wrench for a 3/8 bolt, then there are 1/2 wrench head size for a 3/8 bolt. I have arp bolts that they make with a 3/8 and a 7/16 wrench size for a 3/8 bolt. I called them and they have that listing. They also have these smaller head sizes for the 5/16 thread size bolts too.
63dartman
Well-Known Member
I think a 12 point 5/16 box end wrench will fit just fine. It will also have more places to grab since it is 12 point. I will let you guys know how it works out.
Leigh
New Member
Early 80's smallblock's used a long hex nut manifold nut. I turned those down on a lathe, leaving the hex on the end, past the tube. They worked great in conjunction with studs on the end locations. The other tight locations, I used allen socket screws, and cut an allen wrench tip off, insert then use an open end wrench or the shortened allen wrench with a small tube for leverage.
Leigh
Leigh
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