I'd go atleast 750 miles. But it all depends on what kind of driving you do. I waited 1,000 miles after I changed my clutch on my GSR to even consider getting on it or hard shifting. But at the time I was doing shitloads of freeway driving. Stop and go traffic and lots of city driving will break a clutch in much more quickly. 500 is alright if you sit in traffic all day everyday
Keep in mind though, it's better safe than sorry. Waiting a little longer is better than have to pull it back apart soon