Need a new rear yoke... Help please!!!

[elks]

So I am starting to go through rear straps on my 1972 chevy blazer. I know the rear is a 12 bolt, but I am wanting to upgrade from straps to u-bolt style. Local part houses, are of no help so I need to order online.

I need to know how many splines the pinyon shafts are. Also I know factory it came with a 1310 ujoint. Right now I have a 1 ton tom woods driveline. But am using a crossover rear ujoint. If I can I would like to take that ujoint to a full 1350. So anyone know what I need to get inorder to get away from straps and go to a 1350 ujoint?

My biggest hang up right now is the spline count.

Also I am aware that the set up uses a crush sleeve and what I need to do there...

Thanks a ton.