Well I agree with you on that. It was Reverb, I think, who seemed to imply that single carbs were only good for pottering around slowly (sorry if I misunderstood you on that Reverb). The engine has a 70-9989 exhaust cam, 71-7017 (standard) inlet cam, 9:1 or so compression, T140D exhaust system without any silencer (I recommend this setup - releases a lot of otherwise stifled power), carb jetted to suit. No fairing, 'western' bars and me hanging onto them in my Belstaff coat like a parachute! I've had it over 110 on the clock, but that is a fraction over 100 in reality. I never crouch down for extra speed as that reminds me of kids on mopeds.
I'm building a similar engine but with a twin carb head in racer style. This will have a small (Ducati 900SS style) fairing, clip ons, rearsets etc. It'll be interesting to see how fast that'll go. I reckon well over 120 with the right gearing.