High quality performance parts at the right price made in USA. (12) nuts needed for a direct bolt on. ARP recommends studs over bolts because of the ability to obtain a more accurate torque reading studs provide over bolts. Studs don’t twist as they are fastened down. Additionally, because of this there is less force exerted on the thread of the block, which results in increased block life, especially on aluminum blocks. Replace your stock head bolts with ARP heavy duty head studs. The stud design helps the head and the block equalize the pressure better thereby creating a much more even and consistent seal. It is recommended to replace the head studs/bolts with a new set if the head bolts are ever loosened due to metal fatigue. Reusing an old and possibly warped or stretched head bolts/studs will sacrifice the seal between the head and block and may cause head gasket leak. This is a great an easy upgrade when doing an engine rebuild or building a race motor. Tech Tips: Main Stud Installation Clean and chase appropiate threads in block to ensure proper thread engagment and accurate torque readings All hardware (and caps) should be cleaned and inspected prior to installation, looking for any damage or defects Screw studs into block, finger thights ONLY. For permanent installation, apply loc-tite sparingly to threads. Be sure and install the caps promptly before the cement sets to prevent misalignment of studs in block. Install main caps, checking for binding and misalignment. Lubricate threads, nuts and washers with oil or arp moly assembly lubricant before installation. Note that torque specs will vary by lubricant. Moly lube is more consistent. Have block align honed. Usins the instructions provided with the studs, tighten the nuts to proper torque values three times. NOTE: if using Loc-tite proper preload must be achieved prior to it setting up. ARP studs are made from premium 8740 alloy, rated far superior to aircraft quality materials. Each set is heat treated to 200,000 psi, thread Rolled after heat treating, which results in a stud 1000% better than studs that are thread rolled prior to being heat treated. The kit includes 12-point nuts and hardened parallel ground washers. Using studs will make it much easier to assemble an engine. Studs provide more accurate and consistent torque loading. When you use bolts, the fastener is actually being twisted as torque is being applied to the it. The bolt is thus reacting to two different forces simultaneously. Applications :&#######xA0;Subaru BRZ 2.0L FA20 4 cylinder Scion FRS Toyota 86. &#####x200B;&#####x200B;&#####x200B;&#####x200B;&#####x200B;&#####x200B;&#####x200B. Please allow 24 hours for the tracking information to update. International orders may take extra days to process. Euroexport holds the right to cancel any order at any time. Any product you return must be in the same condition you received it and in the original packaging. Please keep the receipt. Wiseco pistons with part number starting in KE. See our other items. Kit comes with —(12) Head studs —(12) washers —(12) nuts needed for a direct bolt on —ARP moly-lube —instruction sheet ARP recommends studs over bolts because of the ability to obtain a more accurate torque reading studs provide over bolts. Applications: Subaru BRZ 2.0L FA20 4 cylinder Scion FRS Toyota 86.