How big is your track?? Might be an idea to ask what gearing the other guys are using too, as a starting point.
Although the Monster is a high-rev motor, it can probably pull something slightly higher than 6.54:1 on a large track. The guys here run in the high fives even...
Bear in mind the Monsters are pretty *variable*. One motor can perform entirely differently to another from the same batch. If you have more than 1 Monster, good tip is to write the sweetspot ratio on each can as you find it.
Good batteries also do make a difference, if you're talking only a deficit of 4' by the end of the straight. Expensive fix, but them's the fighting facts. You'd better not be using Jaycrap no-label 2700s!!