... not being there and not having the problem before I really can't say....but you should not have to drive any pilot shaft bushing up into the crankshaft.
That said can you get a pair of dial calipers up in there to check the crankshaft hole? It sounds as though there ia a "taper" in the crankshaft or it just plain compresses when you "drive" it in.
I'd take a look at the OLD one vs the new ones....nothing says you can't use your old one unless its messed up. Take your old one with you to the parts store.
Hmmm, I'm interested in what others say and what you find out in the end. Let us know.