How long ago did you score 700 and 710 on GMATPrep?

My advice is that if you absolutely want to hit 740, you should probably postpone. Essentially, you ought to:

1) delete and retake the GMATPrep tests multiple times. You will see an overlap in questions but do your best to solve them anyway (don't just pick the answer you remember, but figure out how to solve each).

2) Go over each question and try to figure out why each wrong answer is incorrect (particularly on the verbal side). This is a lot of work, but you will reap great benefit from it.

3) Since you will start to see a higher incidence of familiar questions, overtime, your score will increase and will eventually overshoot your actual ability. This is ok; the point of these tests isn't really to gauge your ability, but to help you master every question. You will know that you're ready to go in and score 740 when you can hit 760-770 two or three consecutive times in GMATPrep.

You can see the study strategies that I found particularly helpful in my debrief: www.tinyurl.com/gmatpost

Best of luck