If you find a running GenIII with 85k on it, you should be happy to have it.
If you really want to do something to the engine, FIRST, ensure that you have the cams welded. Then, have the secondary intake runners and intake manifold cleaned, replace the PCV valve, spark plugs and you might as well throw in a new set of coils just for the heck of it.
85k is still ahead of the first "scheduled maintenance" and if you do the above along with a good change of fluids and filters (includding trans, power steering and oil) you should have a great engine and be saving thousands over a new engine.