Part #: OUT - ENG - HEADSTUDS. Outfront Motorsports has joined hands with ARP to create an exclusive head stud kit designed with our unique specs and innovative ideas. Look for our special markings and don't accept fakes. Fitment includes various Subaru models such as WRX (2002 - 2018), STI (2004 - 2021), Legacy GT / Outback XT (2005 - 2009), Legacy GT (2010 - 2012), Forester XT (2004 - 2013), Baja Turbo (2003 - 2006), BRZ (2013 - 2017), and FR - S (2013 - 2016). Benefits: It's 25% stronger than 625+ studs and 40% stronger than 11mm ARP 2000's. The reduced shank diameter means no need to modify the head gasket. There's more thread engagement in the block compared to 11mm studs. It uses stock alignment pins without modifying the case or heads. It has been tested to withstand over 200ft/lbs of stud 'pull - out' in the block. The price is the same as 625+ kits, but those require additional block and head machining. Custom large - diameter hardened washers prevent embedding into the head under high torque and HP. Note: Block machining must be done on bare cases, not after the shortblock is assembled.
Using this Outfront Motorsports custom ARP head stud kit is straightforward. First, make sure your engine is in a bare - case state as block machining must be performed before the shortblock is assembled. Install the head studs using the stock alignment pins, which don't require any modification to the case or heads. Tighten the studs carefully, and use the custom large - diameter hardened washers to prevent any issues under heavy torque and high horsepower. As for maintenance, regularly check the tightness of the studs, especially after long - distance drives or high - performance use. If you notice any signs of looseness or damage, replace the studs immediately. Also, keep the engine clean to ensure the best performance of the head stud kit.
