In my Gulf Stream owners manual, which like most, is for more than one model, it states two torque specification settings. It talks of side load, and importance of checking lug torque often.
The chart shows
"Lite" Towables 50-75 ft. lbs.
All other Towables 85-95 ft. lbs.
WARNING! DO NOT OVER TIGHTEN THE LUG NUTS! OVER TIGHTENING MAY CAUSE THE LUG STUDS TO SHEER OFF UNDER CERTAIN DRIVING CONDITIONS.
I have six bolt 5,200 lb axles on my FW. I have two torque wrenches, one tightens slightly more than the other, when set the same. I tighten the lug nuts on mine to 95 lb./ft, with the slightly weaker wrench.
IMO, a spread of 90-120 is too much. IMO, anything over 100 lb./ft is too much on a mid sized RV trailer.
Maybe the OP will come back with the specific info, given to him from his axle manufacturer.
Jerry