[drgage]

I am new to this forum. So I apologize in advance if this is the wrong place to put this question , but I didn't see my car in the list. But here is the situation.

A friend of mine asked me to repair her car for her. I am now in the process of doing it. However I am at a standstill due to the fact that I cannot remove the harmonic balancer off of the crankshaft. I have tried several different means of doing it, including buying a harmonic balance puller from a major auto parts store. But the bolts are too big for the harmonic balancer in itself. I need to find out what size the bolts are but I can't because they are too deep inside and I can't see the threads. I don't know if the threads are metric or american and I don't know what size to have. The car is an Oldsmobile Regency 98. Any help in this is appreciated.
Once again I apologize if this is in the wrong thread. Thank you !.