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WTF?! ARP head stud installation and 13mm 12point socket doesn’t fit head

606 Views 12 Replies 6 Participants Last post by  Jonqdiesel
Has anyone ever ran into this problem on their GE vvti heads when trying to install ARP head studs?! I’ve search and searched and searched and found nothing and am extremely frustrated.

the 13mm 12 point deep thin wall socket does NOT fit inside the groove of where the head studs bolt down. I can start 3 of the nuts on the head studs but that’s it. I will post a photo for reference.

am I supposed to hone out where it doesn’t fit? I thought these were supposed to be drop in, install and go.

please let me know if someone has ran into this problem and what they did to solve it. I really DO NOT WANT TO drill out the spots that won’t accept the socket but don’t think theres anything else I can do??


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I really DO NOT WANT TO drill out the spots that won’t accept the socket but don’t think theres anything else I can do??
You got a lathe? You will need to turn that socket outside diameter down so it will fit the wells in the head. I tried every socket I could find and had the same issue as you. It wasn’t real fun turning down that hardened tool steel but it did it.

You can see it here:

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Man so it made me nervous shaving that much off the socket. It didn’t affect its strength that I can tell. I put the head on and took it off several times, each time torquing all 14 of them bastards to 80ft-lbs. The socket worked fine. I’d have to go measure it to see how much I took off. I’d say 3/16” of an inch?

It’ll be a good “get acquainted” project for a lathe. Chuck it up in a 3 jaw and go slow.

I don’t think it’s a 13mm btw. Should be a SAE 1/2” 12 point. 13mm may “work”.
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Yeah man, you’re welcome. Glad to assist. I’d take the socket set back. 600$ will get you a good craftsman set or even a Pittsburgh from harbor fright. Hell you could just buy the socket by itself.

The ARP studs are reusable for sure. They are not torque to yield like the stock bolts.
Man, I mean that’s a personal choice on the head. If it was OK before, it should be OK now. It’s waaay easier doing upgraded valve springs, stem seals, and clearancing the cams when the head is off. And if you have to do it with the head on the block, then next best is engine out. It’s hard to get in there and get the springs compressed with the engine in - especially with some stiff aftermarket springs. If you keep it all stock, a toyotool is the bomb. If you go aftermarket get a Subaru style compressor. You won’t be able to do it otherwise. Read up on the “rope trick” for valve seal replacement, it’s the best.
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