Absolutely nothing. As a matter a fact the one on the car still works. (not sure if it's original but it's the big heavy original style). I just read that the upgraded starter was a simple and great upgrade for the car.
Please see my response here: what's the favorite replacment starter for these sixes?
I've seen this several times now and made several references to it here, basically gotten ignored. It's all good though. Good luck with whatever you end up doing.