The big twin I had in my chopper made the Vmax feel neutered. Tons more pull and more HP put to the ground. With the 6 speed and about a 7k redline, it pulled just fine up top too.
There are a few street driven 10 sec twins up here, its great to watch them run. There was a couple on "Pass Time" One was a sportster that ran a 10.6 with a messed up shift (Driver said he was over 200lbs and the bike over 600 )and George Bryce's Bagger that went 10.90 with a huge second gear wheellie. Both bikes were all motor. One a 128ci and the other 145ci.
Here is a 10 sec, Street legal Nightrod. Goes to show, you never really know whats in the other guy's hand until the cards are layed out.