Part #: OUT - ENG - HEADSTUDS. Outfront Motorsports has joined hands with ARP to create an exclusive head stud kit with our unique specs and innovative design. Look for our markings and avoid imitations. Fitment includes 2002 - 2018 WRX, 2004 - 2021 STI, 2005 - 2009 Legacy GT/Outback XT, 2010 - 2012 Legacy GT, 2004 - 2013 Forester XT, 2003 - 2006 Baja Turbo, 2013 - 2017 BRZ, and 2013 - 2016 FR - S. 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. It has more thread engagement in the block compared to 11mm studs. It uses stock alignment pins without modifying the case or heads. It's been tested for 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. It comes with custom large - diameter hardened washers to prevent embedding into the head under high torque and HP. Note that 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 block is a bare case as block machining can't be done after the shortblock is assembled. Then, install the head studs into the block using the stock alignment pins without having to modify the case or heads. The reduced shank diameter of the studs means you won't need to modify the head gasket. When tightening the studs, keep in mind that these studs have been tested for over 200ft/lbs of 'pull - out' in the block. The custom large - diameter hardened washers are there to prevent any embedding into the head under high torque and power levels. As for maintenance, regularly check the tightness of the studs. If you notice any signs of wear or loosening, it's best to replace the studs. Also, always follow the manufacturer's instructions and torque specifications for the best performance and safety.
