ARP 260-4702 Cylinder Head Stud Kit

built ej22 franken-motor. worked great.

I like the confidence this ARP 260-4702 Cylinder Head Stud Kit gave me when I was rebuilding my '03 Subaru Forester SOHC engine. I damaged the block's head bolt threads digging out a snapped head bolt. The ARP studs turn into fresh, untouched thread below the lowest point the OEM head bolts will contact so I'm hopeful the repair will last. I did have to clean every bolt hole with ARP's M11 x 1.25 thread cleaner tap and you should too! It guaranteed that the studs tightened to the correct depth. Also, it was tricky installing the ARP washers; they didn't fit into all their cavities in the heads if you install them in ARP's prescribed order. I just had to lay the washers into the head's cavities before installing the studs, instead of after. There was some aluminum flashing on the head that interfered with the washers while they were being installed onto the studs.1.5 year checkup: These studs are holding great. I have no leaks around my head gaskets.

The threads in the block need to be VERY clean. ARP supplies a thread cleaner for $50. The thread cleaner looks just like a tap. This is an issue because it's impossible to clean the head bolt threads so far down in the whole using a normal tap holder. I welded the tap onto a 1/4" 8mm socket. That worked well enough.After using the thread cleaner (thread chaser) the studs installed smoothly mostly by hand.

7,000-8,000 miles since my build and no leaks, no issues. Used my Subaru WRX STI head gaskets on my NA 2.5 RS.

Awesome kit!

These are way way better then the regular head bolts. These fit my sohc ej25 perfectly. It's worth the investment.

Saving this little subaru 2.5 sohc from future head gasket issues

It’s ARP. - just no substitute, but expensive.