Small head bolt hole heads are specifically designed for severe endurance, high compression, high cylinder pressure, alcohol fuel applications. Two head bolts in Small Block Chevy heads are inherently thin with the OEM design. These smaller head bolts add an extra 1/16 inch of material to thin areas increasing the strength of the head. The heads are supplied with four special ARP 3/8 X 7/16 head studs that must be used in this head. AFR small head bolt heads has all the same features and benefits of AFR standard heads.
