Opinions on this here used truck . . .

The 2.93 rear with a 13 is fine. I had the same setup in a 2000 classic xl an ex swift truck and pulled step deck all over the country and Canada. The 13 is not a double over it is a single o/d and 13th is .86 ratio. The way the tranny is geared makes up for the rears. A friend of mine had a 2004 classic xl with a 14l detroit and 3.55 rears with a double o/d 13 and I had no problems running with him on the hills,I actually would out pull him, not by much.