mph to low maybe wrong gears?

secound test and tune was solid and impoved times, but mph are low best time was 11.3 @ 102 mph and 11.47 @109. Im running 4.30 gears wondering if i should have went with 4.56 or 4.88 gears or even have left the 5.13s in it, gonna swap carbs with another 850 i have, gonna try 82 primary and 88 secoundaries and power valve plugs also gonna tune for n20 got to get this pig in the 10s.