Heh heh. Yes, I am rather freakishly proportioned. 6'3" and 250lbs (optimistically). I can still manage to cruise at 25-30kmh (50t - 19t ratio). My aero tuck still has the frontage of a two story house. On two wheels I weigh as much as most tandem teams. I think that qualifies me for ultra-clydesdale status.
Although, within the forums there are a number of riders who are at the 6' + mark. I lucked out when I found the Raleigh in the pics (I think its a 62-63 cm Super Grand Prix). I work with a guy who is 6'8" (and 160lbs) and has a vintage Panasonic in a 66cm size that he has so far refused to sell me. So in the meantime, Its long seatposts & tall stems.
Luckily, the stem goes down as the season wears on and my back loosens up and my belly shrinks.

If you see me in T.O., say hi.

Dave G.