These axles are designed for off-road and circle track racing applications that utilize the Wide 5 (3/4 to 1 ton truck) / Dana 60™ / Dana 70™ type hubs. The 40-spline drive flanges are manufactured using aircraft quality alloy steel, heat-treated, and black oxide coated. The axles feature true involute splines, are heat-treated, polished, and shot peened. The center section spline is available for any spool / carrier requirements. These parts are designed to work with factory 7/16" axle hub bolts or studs. Covers are anodized aluminum with low-profile sealing o-rings. The complete kit is comprised of shafts made from 300M material, flanges, caps and fasteners, o-rings, and retaining rings. Download service bulletin # 0090 axle order form to help gather your dimensions. Pricing is for axles longer than 31".