Most Dana 35 rear axles come from the factory with a yoke that uses thin straps to retain the U-joint. While adequate for stock applications, once larger tires and lower gears are added to the mix, the weakness of the straps becomes evident. When the straps fail, at best you're looking at replacing the U-joint, and at worst you're buying a whole new driveshaft!
Rusty's U-bolt style yoke is a direct replacement for the factory yoke and utilizes U-bolts to retain the U-joint, a much stronger and proven method. This is an excellent upgrade when installing lower gears, since the stock yoke has to be removed anyway. The kit comes complete with an HD yoke, pinion seal, U-bolts, and a pinion nut. Note that many Dana 35s use a crush collar for pinion preload, so use caution when installing the yoke with an existing gear setup; too much torque can further “crush” the crush collar, which changes pinion preload.
Should you need a replacement seal for this yoke, it can be found here: Part Number 40554.