I personally think you'd only get a couple unnoticeable hp at the strip and have to deal with cruddy street manners, especially when cold. You might actually net an overall loss of performance with a single if you end up giving up a significant torque number with a single.
usually single planes really shine on the street in engines that don't worry about torque and they have so many cubes to support that the single is really needed. I'd put a single on a 572 in a heartbeat. So what if your torque drops from 650 down to 620, you can't use it all anyway.