Upgrading your stock headbolts is a necessity when building a upgraded motor.
Here are the Mazworx SR20 headstud kit.
These are the correct length that will completely bottom out and provide extra clamping force needed. ARP2000 is capable of achieving clamp loads in the 215,000-220,000 psi range. ARP2000 is used widely in short track and drag racing as an up-grade from 8740 chrome moly in both steel and aluminum rods. Stress corrosion and hydrogen embrittlement are typically not a problem, providing care is taken during installation.
Made from ARP2000 material
220ksi tensile strength
Straight shank/bullet ends from complete bottom out