Mark WIlliams - 9" Ford Standard Steel Spool (35 spline for 3.250" case)

All Mark Williams steel spools are precision machined from 4140 steel forgings on CNC machinery to ensure accuracy. The ring gear register and bearing diameters are precision ground with the spool mounter on a special arbor to assure concentricity between the splines and the ground surfaces. The final grinding operation also ensures zero runout on the ring mounting surface. Engineered for maximum reliability, MW spools also have an increased cross-section under the ring gear register to prevent ring gear deflection. MW spools are heat treated in-house with the same austemper through hardening heat treat process as MW's Hi-Torque axles. Mark Williams steel spools are offered in both standard and lightweight versions. The major differences are the addition of lightening holes drilled through the hub of the spool and a profile milled ring gear flange. This reduces the weight by as much as 25 % over the standard version without sacrificing the strength of the spool.