I'm new here and tried to read through this thread before asking...I recently picked up a "95 3500 HD 2WD dually w/19.5s that has a 4L80 and a Dana 80 rear diff. that according to the tag it is 4.63 and noticed everyone else seems to have 3.42,3.73,or 4.10. It needs a rebuilt 6.5L and wasn't running when I bought it, so I have no idea how it is at highway speed or the mileage. I'm in the process of building a dump bed for it, and it won't see speeds above 55mph very often and will be used to tow on occasion. Does this sound like the correct ratio for this truck and it's intended use? I apologize if this is a dumb question, but I'm new to all of this... /// tim