K3vet Arp Head studs

Hi guys, im having some trouble with my ARP headstuds in the head as there is not enough room to fit the bolt. Has anyone else experienced this problem or know a way around this?
The studs are 10mm not 9mm like factory. The head and block has been drilled already. They work perfectly on the block etc

Picture? I had trouble on a diff head getting the nuts to fit. Internal wrenching ones that use an Allen key were needed. I did contact ARP and they helped a bit. The project is at a halt and I’ve not purchased these nuts as yet. The nuts that would have worked for me are from the Audi kit and can be seen in the image below (they look like short tubes) image

that great news! Whats the best place to look at getting these or is it best to ring ARP?

I called ARP in the USA. Was going to do a special order. The guy I spoke to said he could send the nuts that are normally part of the Audi kit. You’ll need to confirm the thread diameter and pitch and see if they have them already. 10mm should be a normal size. But M1.5 or M1.25 is what they’ll need to know?

Fantastic ill get in contact with them and fingers crossed its in stock

Thank you so much for your help! Would be lost without the knowledge your provided!

Hey guys. Apologies in advance for resurrecting this thread.

I’ve searched L2D and am also somewhat curious as to what solutions there are for the K3 series engines, aside from having to cut down Nissan studs and / or the Audi kits that is mentioned here. I did email ARP and the solution they suggested was Toyota 4/5E and FTE head bolts do work?

Here are the specs at https://www.jegs.com/i/ARP/070/203-3801/10002/-1

Thread Size (mm): 9 x 1.25

Are head bolts less desirable than studs and nuts?

Thanks guys for your time.

A stud is always better. Bolts will twist along the entire length. Like a torsion bar. With a well lubbed washer and nut they will spin on the top thread of a stud. The stud should barely twist at all. So studs give more accurate torque down constancy and accuracy of torque reading (or angle if tightened by such a method). Arp are a good thing even if in a bolt. The bolt with internal wrenching (Allen bolt) is needed as a socket would not fit on the head of a nut and stud set up. As you may be aware some Audi and vw kits use a stud with a long nut that is internal wrenching

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Thanks Mr Gormsby. I’m hoping I wouldn’t need to get the block rebored for the studs but it’s looking like I should get it done. Basically anything M10 x 1.25mm or M10 x 1.5mm metric head studs would be good right?

I guess I’ll have to email ARP again and see what other solutions are available aside from 4/5EFTE engine bolts.

Thanks for your time and replies.

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The 1.5mm pitch is better in a casting as less likely to pull out. Finer threads (1.25mm comparably) though bolt up with more torque for less applied effort (think triangle with shallow ramp so easy to push up hill)

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Cheers thanks Mr Gormsby thank you very much for your help. Really appreciate sharing of knowledge. Always learning something new whenever I access these parts.

HI dev. Did you manage to source for a ARP stud that does not require machining? We tends to use mitsubishi 4G93 ARP stud but it require so much works and prone to failure rather than reinforce it.

Hey thefiztec,

I sent you a PM.