I've only ever made one big cock freesite and I almost didn't submit it because the guy, and yes, he was black, didn't have a huge dick. I think it was more like a "good" sized one. Or maybe it
was huge. What's the standard for judging huge-ness? They all look monstrously massive to me.
Penisbot
has a guide on it's listing secrets page that gives you an idea of which categories are the most popular regarding submits, which might help.