Hey guys, I'm in the middle of removing my head and I'm at the point where I have to remove the head bolts. Manual says to use a 13mm allen socket, which last time I checked, 13mm is quite large. I thought it meant 13mm socket and disregarded it as a typo. Looked at them and it seemed to me a 12-point 13mm socket would do the job. Bought it but it doesn't fit. So I guess they must have mean 6mm allen in the manual. Am I correct in assuming this?

I just did the exact same job last week...you'll need a 12mm 12pt (deep preferred) socket .

$2.XX @ your local Princess Auto.

I used a 1/2" breaker.

Good luck, brother.

Btw, what manual are you using?

12mm? WTF the 13mm didn't fit over top of the nut! Ok, I'll try it...

It's the Haynes Manual. I couldn't even conceive taking any of this on without it.

You mentioned nuts. Are you dealing with head bolts or head studs?

The reason the Haynes is calling out an allen wrench, may be because some of them did come with Socket Head Cap style bolts:
http://i104.photobucket.com/albums/m178/MizumoAuto/MizumoAuto/Head-Bolt/ES71175/ES71175a.jpg

Is the block/head studded? could be ARP.

It was a 10mm allen key socket driver, from what I remember.

6-bolt motors use the allen key socket driver.

7-bolt motors use a 12-point socket.

I don't recall the sizes exactly but I believe it's a 10mm allen key socket like Adam stated and the 12-point socket should be a 12mm. Again, it totally depends on 6-bolt or 7-bolt motor.

Ah yes, very good call. I wiped the fasteners down and with a light I could see ARP is stamped on the ends of the studs. Cool! But it would have been nice to know these were installed...

So how do you remove a head with ARP's in it? I took a closer look and maybe a 15-16mm 12-point deep socket would fit. Is there a specific size that comes with the ARP kit?

14mm, 12 pt deep socket

Wicked. Off to Cisco I go. Thanks all!

By the way, thought you guys might like to see the carnage.

too much boost? or bad tune?