My truck is a 1997 Freightliner FL-60 "Western Flyer" with
a Cummins 8.3 (mech) 275/810 and an Allison 6 speed automatic
transmission. It has a Rockwell 19K rear axle with 4.33
gears.
I have added a "Taylor Wing" and a Purifiner bypass oil
filter.
I pull a 40 foot fifth wheel weighing 23,000 pounds and
the combined weight is 37,500 pounds.