Haven't had one (yet) but 3 would be nice
I think you won´t be satisfied with three. Five would be better for you.
That might take all night. hehheh
I think a gangbang would be considered with 4 or more, maybe even 5, one big black hard cock for each hole and each hand. But everyone has their own preferences
How many BBC does it need for a good gangbang of a white lady ?