I got a new set of Jaco Eliminators (old ones were way worn and teh OD was real small), and went up 2 more teeth on my pinion (22t).  I got 54.9 mph out of it today on a 3S.  The motor and ESC are still still cool so I will try out a 24t next time I take it out, I think I should be able to at least break 60 with this setup.