If you are building an upgraded motor, an upgrade to the factory head bolts is necessary.
This is the Mazworx SR20 Head Stud Kit.
These are the correct length to fully bottom out and provide the necessary additional clamping force. ARP2000 can achieve clamping loads in the 215,000 to 220,000 psi range. ARP2000 is widely used in short track and drag racing as an upgrade from 8740 chromoly for both steel and aluminum rods. Stress corrosion and hydrogen embrittlement are generally not an issue if care is taken during installation.
Made from ARP2000 material
12-point
Tensile strength 220ksi
Shank/bullet end extends straight from fully bottomed out
Before Ordering
〇 Regarding Import Consumption Tax
At the Shaftoya shopping site, we cover the import consumption tax incurred at the time of import, so there will be no additional charges beyond the total amount paid at checkout.
〇Checking Compatibility
Since our entire product database is based on North American vehicles (USDM), please confirm whether or not parts can be installed on Japanese vehicles (JDM) before placing your order. (If you are unsure whether a listed product is compatible with your vehicle, please feel free to contact us. Our support team will be happy to look it up for you.)
If you place an order without confirming compatibility, we cannot accept returns due to incompatibility.
Please note that even if products are sorted by selecting the year, manufacturer, and vehicle model using the tabs on our homepage, this does not necessarily mean they will fit Japanese model vehicles without modification.
All product descriptions have been translated into Japanese using translation software. As there may be confusing expressions, please contact us before ordering if you have any questions.
○ Regarding Shipping
Shipping costs are paid at the time of checkout. Shipping estimates are calculated automatically once you enter your shipping address on the checkout page. For large items such as body parts, the automatically calculated shipping cost may occasionally differ significantly from the actual shipping cost. In such cases, we will contact you individually via email.
Basically, all products are shipped internationally from our US warehouse. Unlike domestic shipping in Japan, international shipping takes about 7 to 14 days, so please allow plenty of time for your order. If you are in a hurry, please contact us in advance to check the delivery time. Note that all products are transported by air. They are never shipped by sea.
○ Regarding Japanese Vehicle Inspection (Shaken) Compatibility
Basically, all products we handle are designed and manufactured outside of Japan. Please understand that they are not compliant with "Japanese vehicle inspection (Shaken) standards," and we cannot provide documents such as strength evaluation reports for Japanese vehicle inspection purposes. Therefore, all parts are sold for use on "circuits, private property, or off-road," and installation and use are at your own risk.
○ Regarding Warranty
Please check the contents immediately upon arrival. Since all products are shipped internationally from outside Japan, there may be shipping damage to the packaging or the product itself. Please understand that we will only provide returns, refunds, or replacement exchanges for items with shipping damage, defective products, or items different from what was ordered if you contact us within 7 days of receipt. Furthermore, for products sold through our company, warranty-related support will be handled "exclusively through us." Please note that we do not handle support through other companies or distributors located in Japan.