biz, I would not be worried about the motor IF it has been well cared for. I have an 88 with a 3.0 and automatic with 276k on it and it runs like a champ. Mine runs great, doesnt leak a drop of anything, has all the power I need, gets decent MPG (19) and has cold a/c.
I drive it around 300 miles a week and run all over NM with no worries about breakdown.
Mark