Z20 ARP Main studs

ARP recommends the use of main studs over bolts whenever possible for several key reasons; First is the ability to obtain more accurate torque settings because the studs aren't being twisted into the blocks already-used-at-least-once threads. This also means that there is less force exerted on the blocks threads, which contributes to improved block life. The studs, being a slightly larger diameter than the fairly slack OEM bolts, ensure a more accurate alignment of the main caps.

All kits come with hardened and parallel ground washers and high quality nuts. They are manufactured from a special 8740 chrome moly steel, heat treated in house to 200,000 psi tensile strength, and then thread rolled precisely to the high tensile J-form spec to create a fastener 2000% stronger than others.

These ARP main studs have been specifically developed for the Vauxhall Z20 engines

Full set including a sachet of ARP's assembly lube, for correct torquing.