Ok I have looked all over arp and other websites and I get two different sizes for these headstuds. I need to get a time sert for one of them. Does any one know what the size and pitch is. I know it fits a imperial size 7/16-20 but arp also says m11x1.25. Any help would be appreciated.

 

Just to keep a record,

After taking a stud to an industrial hardware store, I found that the tightest socket you can fit on todays ARP L19's headstud nut for the evo 8/9 is a 12 point 1/2 " deep socket.

The last thing you want to do is put almost 100ftlbs of torque wrench on a loosely fitting socket.
Metric 13mm socket was too lose because it's 0.3 mm bigger than a 1/2" socket even thought it did have some bite. 7/16" was too small and didn't fit.

-pal215

 

We have m11x1.25 head bolts/studs.