arp cylinder head bolts, hex head, high performance, for pontiac, 326-347-370-389-421, w/ d port heads (1964 & earlier), kit

ARP High Performance Series head bolt kits are tough. They are rated at 180,000 psi--15 percent stronger than Grade 8 fasteners. They come available with a reduced wrenching hex head or 12-point head that help eliminate the need for valvetrain removal when re-torqueing cylinder heads.