Callies Ultra connecting rods are produced from Timken steel that is formulated to our exact specifications. Each step of the manufacturing history of every Ultra connecting rod is meticulously maintained by our manufacturing team. You can be confident of the material and workmanship of these quality components. Specific design features enhance the Ultra against specific loads and stresses which are applied to connecting rods subjected to high load, high RPM applications. Ultra connecting rods are fastened by high alloy cap screws made specifically for severe duty service by ARP Inc. Produced with rolled threads, these unique bolts offer improved thread engagement for a smoother more consistent net clamping load. To eliminate deformation and extrusion, only AMS 642 bronze alloy is used within the wrist pin housing bore.
*Note – Blocks utilizing piston oil squirters may require some clearancing on the connecting rods.