I was going to post this as a new thread, but saw this and figured . . . may as well cut on clutter on the board, eh?

So . . . my question is this:

I know of someone who's about 6'4 (and with a good natural build . . .he doesn't work out at all . . .but is somehow rather thick and built body-wise . . not that that will particularly matter . . .but just thought I'd throw that out) and has a cock that's about 4 or 5 inches long and about 2 inches thick (in diameter) when soft. How big, then, would be a reasonable guess as to how big he'd be when hard?