They are the 12 point hex head, with the 1.000" underhead I think with the 3/8-16in thread size. Does anyone know how the sizes in the head is compared to the 11mm size of the Jet Hot header bolts? Are they smaller? I see they have a nut that goes on them, I hope these don't back out!

 

I assume you mean washer and not "nut": any bolt that doesn't lock can back out. The bolts should be checked after initial heat cycles and checked every so often for insurance. The advantage of a 1' bolt becomes obvious if you have any backing out. JMHO

 

BTW, I have never seen a 12pt hex bolt. Like ever.

 

Oops I didn't mean to say hex, just a 12 point external head And a washer, what a long day.

 

Ok so I got the bolts in, the heads are 11/32. I only have 6 point sockets that won't tighten them down all the way. I can't seem to find a 11/32 12 point combination wrench OR socket anywhere, do they make them? If it's not standard, what size would it be metric? Anyone with these ARP bolts can ya give me a hand?

 

Ya can get a wrench or socket at Sears.

 

Just found it. Searched over 15 pages and it was on the LAST one. The nearest Sears is like 30-40 minutes away and I'm without a car. Lowes doesn't seem to carry these either.

 

Will most of the header bolts go in with relative ease? I just want to make sure I am not crossthreading. I can't tell if they are going in straight though. Some of them stop like half way through with the 6 point *I obviously need 12* but maybe it just reached a tight spot. A lot of them I was able to hand screw mostly in.

 

I'm pretty sure I have the same bolts as you, and I used the box end of an 8MM wrench...works fine.

 

So I went to Sears and got a 12 point 11/32" socket and combo wrench, to my luck, they are TOO big. I don't get this, the 11/32 sockets I used before were fine until it got tight than it would slip, I thought that all that I needed was a 12 point. Do I need a 12 point socket to tighten it? Should I try an 8mm? I meant to bring the bolt with me but I forgot. The 8mm sockets that I have don't fit this, and 9mm is too big. Any ideas?

 

Post up the part # of the bolts you have....

 

I got it, it did end up being 8mm, but all the 8mm sockets I had didn't fit. Found out that one of the bolt holes is crossthreaded, doesn't seem too bad, wonder how much that would cost to get fixed.

 

3/8-16x1", 12 Point, needs a 12 point 5/16 wrench/socket

 

That's it right there. They're good bolts, never had one back out.

 

I like them so far, haven't been able to fire my car up yet. I'll have to go with having 1 bolt out, and one allen key bolt in. I crossthreaded so I have to wait till I can get it tapped. They seem to tighten down fairly nicely, and fit perfect next to my header tubes.