As a longtime member, and frequent webcammer, I would suggest that the question you ask, will produce the following:
a) a large number of guys claiming 8, 9, and 10", who don't have photos or vids in their profile/gallery.
b) another smaller number, (but still substantial), will claim the above sizes, and have pics in the gallery, but it will strain your imagination (and insult your intelligence) to believe they are actually that size....
c) a still smaller number will actually have a 8 or above cock, MEASURED ON THE TOP SIDE OF THE PENIS, which is the way they measure for the size surveys (otherwise, your cock gets longer if you have low hangers, etc.) I'm sorry for the use of capital letters, but most of the time, when I cam with a guy claiming 8, he is usually about 6 or so (e.g. the same size as mine).
d) Welcome to LPSG, inspite of the gross exaggerations, it's a cool place to chat !