I have never seen a penis that I thought was 8+ erect measured properly. I've seen a few here and there that I knew were 7+ in length, but, again, they've been rather rare occurrences.
As regards major girth, I've seen Manuel Ferreria and Shorty Mac....but they're SUPER rare. Big girth is even rare than big length.
I do believe that an erect penis that would measure over > 8 or 8.5 in length would be somewhat anatomically dysfunctional in the state of sexual excitation (erection issues, etc.)
People will believe anything to fulfill their "big dick" fantasies. I've seen intelligent people fall for these absurd claims.
I've seen so many photoshopped pics (rulers, etc.) Folks, it's not that hard to tell that these dicks you see are not 8+. Look at a ruler and use common sense.
BTW, the biggest dick I've ever seen in porn belongs to Shane Diesel (penis volume: combined girth + length). Yes, I am taking into consideration camera angles, etc. And, no, he's not a small-framed man. He's a very well-hung man - one of the biggest out there. This is coming from someone who knows "reality" size. 99.99999% of men cannot even hold a candle to him.
(PS Shorty Mac's dick is too freakish-looking to count lol, particularly the girth)