1996
Ask if they will split the cost of a transmission service. That will tell you about the state of the truck. If the transmission is good, it seems like a good deal.
It is 1.875" I took mine to a machine shop I used to work at. I may make a wrench out of a piece of 1/4" plate and a piece of oak for the handle.
My water pump failed without warning. One of the bearings went and the belt pulled the pulley over so far it chewed a groove in the casting.