I think the truck starter has superseded our factory one. At least when I replaced mine that's what they gave me. And don't listen to the parts store idiots. Just because a starter works on their bench doesn't mean it works in car. A bad starter can spin when no load is applied, seen it in person.. That bench is a good way to get out of warranty claims and nothing more.
Like the other guy said, make sure each bolt mounting boss is equal length. Our factory one has a short boss and long one, the short one is bad about breaking and taking a chunk of engine block with it!
98 Trans Am