MAP Ultimate Duty H11 Head Studs (Subaru EJ20 / EJ25)

Consider these an insurance policy for your head gasket...

If you're looking to make big power (proven over 1000+ WHP) but don't like the idea of lifting your cylinder head and replacing head gaskets frequently these are exactly what you need! These studs are manufactured specifically for us by A1 Technologies and utilize an H11 material that is much stronger than the typical 8740 chromoly and yields a tensile strength of 260,000 psi. They are also provisioned with a hex broach on the top of the stud enabling you to install them with the cylinder head on the car if necessary.

What is so different about these head studs?

At first glance these may appear to be similar to the other ARP and A1 Technologies head studs available on the market, but that is simply not the case. The MAP Ultimate Duty Head Studs include an additional feature known as a "dog point" (shown below) that seats the stud in the block and pre-loads the fastener for an accurate and repeatable torque sequence.

Revised August 2012 to address concerns with thread length and dog point engagement.

9/16" Hardware Upgrade

Although we haven't had any issues in house with the standard hardware that is supplied with these kits, there were numerous requests for the 9/16" drive nuts and larger OD washers that are included in the standard ARP kits. Now you can have your cake (H11 head stud kit) and eat it too! (9/16" drive).

Applications and Notes

• Subaru EJ20/EJ25 Series

Torque Specs

• 100 ft/lb With Lube