Need some repair help !

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 !.

You have removed the big nut from the center of the crank and the 3 or 4 nuts that hold the pully on, right?

All balancer puller kits I have seen come with a variety of bolts with different threads, and one of these sizes always works. If you have bought or borrowed a kit, I suspect it is incomplete and some bolts are missing.

Try a tool rental place. It's cheaper than buying a puller.

Or try this:
You should be using 2 or 3 of the bolt holes that were exposed when you unbolted the pully. Therefore, the bolts you removed from the pully will be the right thread. You can easily match up that thread size in a longer bolt.

I finally got all that done !. I'm almost completely done with it. Only about two more hours of work on it and I'll finally be done !. Thanks for all the help !.