Saturn Repair: Crankshaft replacement, rod bearings, sc2

Question
My younger brother has a 93 SC2 that started making a continuous tapping noise that increased with RPM.  I diagnosed bad rod bearings and left instructions to read the book and replace them.  He drove the car till the noise was so bad he was finally afraid to drive it.  My step father finally replaced the rod bearings I came back to reassemble the car which started right up and sounded great...for 5 minutes.  Then the tapping returned quickly and the engine died before I could turn it off.    The journals of the crank look fine and the rod bearings show some sign of wear (duh).  How can I establish the crank is still true?  I suspect faulty installation of the rod bearings but am willing to replace the crank if need be.

Answer
I would almost guarantee faulty rod bearing installation, especially if they (the old ones) were put in backwards or out of order.  You're messing with danger if you don't take that crank to the machine shop and let them mic it for you.  I will venture a guess that you will need a new crank and an entire set of bearings.  Let me know how it comes out.

Chris