What torque for rear diff. yoke?

I changed my rear pinion seal. I marked the nut so as to tighten it back to the same spot so the crush thingy inside is right. I'm up to my mark now but the threads are kind of stiff all the way so I'm not sure if I should go around one more time or not. Does anyone know the proper torque spec so I can do it by torque? (93 GMC 2wd pickup) Murray