i have a center chunk 489 with a small yoke i need to know does any one know if the spline is a 10 or 29 spline and can you change the yoke for a large yoke or any one have u bolts for a small u joints let me know thanks

Youll have to pull the nut off the yoke to count the splines, only way I know of.

Are you wanting u-bolts or just the strap and bolts? Cause the strap and bolts off the small should work on the big or small yoke, at least the bolts for sure.

If it's a stock gear set it should be 29 spline. The straps are different for small and big joints. U bolts require a different yoke altogether, I've never seen one for a small joint.

The 489 in stock form has a crush sleeve to set the pinion bearing preload so you can't just take the nut off and then tighten it back up.

489 pinions came with either spline count.

If the pinion nut accepts a 1 1/8" socket, you need a 10 spline yoke. If the pinion nut accepts a 1 1/4" or 1 15/16" socket, you need a 29 spline yoke.

Billet steel 7260 (small) U-bolt yokes are available in either spline. A more economical solution is my forged steel 7290 (big) U-bolt yoke and a 7290/7260 conversion U-joint.

E-mail me if you are interested.