Anyone have a value for the tightening torque for the 8 differential half bolts. Can find nothing in specs and don't know the bolt strength for sure. I usually default to grade 5 with Ford bolts, but on this it may be grade 8 so torque would go to 119 ft-lbs, versus 78 ft-lbs for grade 5. appreciate any input before I make a mistake.

Torque specs are based on the load and application, not the grade of bolt used. Bolt grades each have torque limits and vary according to size, those torque limits have nothing to do with their actual application.
Just because you use a higher grade bolt than the original for the same application doesn't mean you torque that bolt higher.

I might be tempted to strip it clean of all oil, thread lock and German Torque.

"Guttentight".

Clean and thread lock is a certainty.

No one else has chimed in? Look at the heads of the bolt and then see if those are Grade 10 bolts.