Yes, lots of differences... Most of the sprint car ones use a one peice axle with an inboard brake. It has splines on the end and the wheel slides on them, probably not real practical for the street. Many of the late model quick changes use a wide 5 hub and would require purchasing new hubs for decent wheel selection... Most all the race type quick changes run a spool rather then a differential, again not a good thing for the street...

There are companies selling brand new ones with a hub and brake made for the street, might be some around used, too.