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Header bolts, allen head vs."regular" bolt heads?

8391 Views 6 Replies 5 Participants Last post by  abn
OK, After several days off, and finally getting my @$$ in gear, I started on the headers this afternoon ;-D Passenger side wasn't too hard, Trans dipstick was in the way, and export brace had to go, but it fits. The drivers side was another story. Steering box, value pan cover, export brace, etc. all caused problems, but after two beers (could have use MORE!), and endless twisting & turning I got them positioned to bolt on. I did however wait too late to get the header gasket & bolts (I just test fitted the headers to make sure they matched up right.). I don't think there will be anyway to tighten regular header (hex?) bolts, and i'm wondering how I can torque down allen heads (30, 40, 50 lbs, correct?).

ARP make allen head header bolts?????

More question to follow. Tryin' to get my post count up, LOL!

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Hi, I always had better luck with regular head bolts in headers they are a pain but if you get a crows foot wrench you can get them. I'm also uping my posts LOL John

Opal frost pearl metallic 67 coupe
also have a 95 opal frost pearl G/T BOSS edition convertible belongs to swmbo
Depending on access, I've used both in the past...sometimes it's easier to get an allen wrench in there and sometimes it's easier to put a wrench on it...

The small hex-head bolts which normally come with headers are a good compromise...they are what I've used predominantly in the past...I recommend using hardened lockwashers (not regular ones) with this type bolt to retain them over the long term

Torque? Most header bolts are grade 6 or 8 so I'd torque them into the 25-30 lb ft range..... for me that's good and tight with a 3/8" drive ratchet...or really leaning on a 5" end wrench *G* Allen bolts are Grade 9 so you can torque those into the 30-35 lb ft range...
Note, the torque specs aren't necessarily reflective of the ultimate tensile strength of the fastener material but a compromise due to using the lockwasher (it does most of the retention). Be sure to use anti-seize on the threads...

ARP makes 12 point headed header bolts (small dia). They are also available drilled for using safety wire.
"If you're under control you're not going fast enough"
Parnelli Jones
I've always just used "regular hex" header bolts. Sometimes, all you can get on there, though is an open end wrench. Stage 8 makes some very cool header bolts, that have a retainer that slips over the chromed bolts that prevents them from vibrating out.

When you go to install the bolts (no matter which kind you chose), start ALL bolts just barley before tightening any down. Then put a few turns on each rotating through all of them to "draw" the header up to the head. If you start one and put too many turns on it, you'll find as you get to the other end one or 2 bolts can't be started. Remember patience is a requirement when installing headers.

If you always do what you've always done,
You'll always get what you've always got
My vote is for the ARP 12 point stainless set. They are the easiest to work with
by far. Destroy a box wrench on the grinder, make the loop as small and thin as possible
then use it to do the bulk of the turning. Tighten fully with a different wrench

M.C.A.# 50000
It really depends on the header...with my hedmans there are some bolts that don't allow a straight shot (maybe one of the snap-on type ball end allen wrenches can get these but I'm not sure)...on those a hex is the best as it can be tightened with an open end or crowfoot wrench from the side. I've used the twelve point ARP stainless bolts and they are great if you can get a relatively straight shot at the bolt or use a twelve point "ignition" wrench from the side. All in all I think high quality small head hex bolts will be the best shot at making sure you can tighten all the bolts.
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