Alternator Pivot Bolt

[bandita]

A friend is helping me change out my alternator on my '72 C10 Cheyenne. The pivot point has a "pin" (not sure of official name) that was really snug into the alternator. We had a heck of a time pulling that pin out far enough to pull out the alternator. And now, we can't get the pin back snug into the new alternator. I'm afraid to hammer too hard and warp the pin. The pin has an open slit that runs across so my friend tried vice grips too to shorten the diameter but as soon as the grips are removed, it goes back to original size (and the grips are too big to leave it on the same time as inserting the pin into the alternator).

My friend says that it's not important to have the pin fit snug into the alternator because the bolt is long enough to hold it in place, along with all the other attachments that's helping it keep the whole unit in place. My other concern is that the pivot bolt no longer tightens snugly like it did before. I'm afraid that vibrations over time can cause the bolt to inch it's way out. I'm thinking that if it wasn't that important, why wasn't the easy way like that done before (not inserting the pin into the alternator)?

So, is it important, and if so, how do we get the pin back into the alternator? Any special tool needed?