miles wouldn't be right if it was towed all the time my guess is i'd check wheel bearings and u-joints toward the top of the list then go from there the engine may have less than 100k depending on how much they really drove it. Either way its still a old truck see if they will let you do a compression test on the engine. On the V6 manual 1st to 2nd gear syncros wear out pretty good around those miles so take it for a drive in the morning see how smooth it shifts.

89 2 dr turbo diesel
89/88 "Backwoods sas"