Brand:-ARP CAM DRIVE Stop worrying about the survivability of your camshaft drive Through-hardened shaft forged from ARP2000 chrome moly steel with corrosion-resistant oxide finish Rated at 220,000 psi for excellent reliability Threads are form rolled 9/16' by.625' on the cam end, and 3/8' hex on drive Concentricity is.001 T.I.R., between shaft and hex; 1' long ItemNumber#A149340005