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?? Is a special socket needed for removal of ARP head bolts

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jamel16

15+ Year Contributor
282
234
Aug 6, 2004
Richmond, Virginia
My question is , is there a special socket ( thin wall) needed for removal of the Arp head bolts. These were on the car when I purchased it, and i'm doing a full rebuild. I have tried all my metric sockets, and the 11 and 12 mm will not fit( too small) and the 14mm is to big. Any help is appreciated, also this is for a 1g 6 bolt.
 
My question is , is there a special socket ( thin wall) needed for removal of the Arp head bolts. These were on the car when I purchased it, and i'm doing a full rebuild. I have tried all my metric sockets, and the 11 and 12 mm will not fit( too small) and the 14mm is to big. Any help is appreciated, also this is for a 1g 6 bolt.

I believe the 6 bolt ones are 13mm 12 points.
 
Wow. It's almost like you answered it yourself. 12mm to small and 14mm to big. Not to tough. And being one a stud a deep is needed. And you can see they are 12 point nuts so again an easy one.
 
On my motor, they are 1/2 inch 12 point. I have a 7-bolt, so it might be different, but it can't hurt to try. Based on what you've seen with the metrics you've tried, it might be worth looking at the 1/2.

Matt.
 
On my motor, they are 1/2 inch 12 point. I have a 7-bolt, so it might be different, but it can't hurt to try. Based on what you've seen with the metrics you've tried, it might be worth looking at the 1/2.

Matt.


7 bolts are 12 mm... which happens to be very close to 1/2 inch, but it's not.

By the way, the fitment is tight so getting a larger than normal socket in there doesn't work. your best bet is a cheaper chrome deep well socket.
 
7 bolts are 12 mm... which happens to be very close to 1/2 inch, but it's not.

By the way, the fitment is tight so getting a larger than normal socket in there doesn't work. your best bet is a cheaper chrome deep well socket.

12mm = .468
13mm = .507

Some metric sets don't come with a 13mm because you can use a 1/2 in.
 
6 bolt ARP head studs are 14mm. 7-bolts are 12mm. I had to go to pep boys and buy a single 14mm socket to do mine.
 
I know for sure 7 bolts are 12 point 12mm, I'm 99.9999999% sure 6 bolts are 13mm 12 points. They are def. NOT standard sized and you don't need a deep socket either.
 
I also have a 12-pt 14mm I purchased for 6-bolt ARP headstud nuts, which I have used several times.
 
I know for sure 7 bolts are 12 point 12mm, I'm 99.9999999% sure 6 bolts are 13mm 12 points. They are def. NOT standard sized and you don't need a deep socket either.

Wrong...
Let only say something if you have 6 bolt ARP's...
The socket you ned is a 14mm Deep 12 pt.
I bought one at Sears for $5, I only use it for my head studs.
You will need a deep socket. he stud stick through to far for a normal socket.
If it not a 14 maybe you have a 7 bolt or they are not ARP's.
 
I pulled my head off yesterday (7-bolt block/6-bolt head/7-bolt head studs). Used a 13mm 12-point deep socket.

For 7-bolts:
When reinstalling, lube up the threads, washers and nuts with a moly lube or ARP fastener lubricant, and install again with a 13mm 12-point deep socket using the shortest extension possible with a torque wrench in the proper installation pattern (manual).

Jamel16 - A 6-bolt uses ARP head studs that are 1mm larger in diameter, and use a 14mm 12-point deep socket.

For 6-bolts:
When reinstalling, lube up the threads, washers and nuts with a moly lube or ARP fastener lubricant, and install again with a 14mm 12-point deep socket using the shortest extension possible with a torque wrench in the proper installation pattern (manual).
 
The OP stated he was trying to removed ARP head BOLTs, not studs. So maybe they are different size. I don't know I have never used there head bolts for a 4g63.
 
The proper socket for the 6-bolt arp head stud nut is a 12 point 14 mm. PERIOD. If it doesn't fit then you have improper components or you do not have ARP hardware. Doesn't it say ARP on the stud? You mentioned "bolts". Do you have studs or bolts?
 
The correct sizes are not metric. On my old regular arp for a 7 bolt, the nuts do not have any marks on them. A 13mm 12pt will strip if you dont hold it perfectly steady. The correct size that fits the best is 1/2 12pt.

My L19s newer nuts have 7/16th (stud diameter I think) written on the side but a 1/2 12pt is needed. Using this size I was even able to remove badly stripped nuts.
 
Kinda OT, but on the subject of ARP headstuds, if you get dual valve springs the nuts will no longer clear. ARP sells a nut with a smaller collar, on my 7 bolt head I needed 4. The two middle, top right, and bottom left. I never see this information on here and it seems like a problem people would run into commonly.
 
The correct sizes are not metric. On my old regular arp for a 7 bolt, the nuts do not have any marks on them. A 13mm 12pt will strip if you dont hold it perfectly steady. The correct size that fits the best is 1/2 12pt.

My L19s newer nuts have 7/16th (stud diameter I think) written on the side but a 1/2 12pt is needed. Using this size I was even able to remove badly stripped nuts.

Never had this problem with my L19 studs. I used a 12 pt 13mm socket with no problems or stripping.

7 bolt is 13mm 12 pt
6 bolt is 14mm 12 pt
 
Yes 6 bolt is 14mm and 7 bolt is 13mm post was to the guy above me sorry I forgot to quote it
 
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