My 88 has a 4.2 with the auto. A little underpowered but runs fine.
I was always told to rebuild what you have if it is in decent shape. They you know what you got. If you want a rebuilt one I bet it has probably had a hard previous life that you dont want to inherit. I went down the rebuild road one time. It did not last 50K until it developed a serious knock. Upon teardown there were 2 #4 rods and the bearings were shot, which took out everything that needed lubrication. Nothing rebuildable left. Find a mechanic you can trust and he will know the best rebuild shop for the work.
