Callies Ultra I-Beam Connecting Rods for Nissan GT-R VR38DETT BBC Journal

Ultra connecting rods are made entirely in the U.S.A. Every Ultra connecting rod is produced from specially formulated TimkenSteel 4330V steel. This material is then precision forged in Michigan and fully machined in our Fostoria, Ohio facility.

Many geometric nuances have been incorporated into the design of Ultra connecting rods. These 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.