Because questions are assigned a range of weights, it's hard to project what would have happened if you were able to answer the last few questions correctly. Of course, you do not know whether you guessed correctly or incorrectly on the last two quant questions, so it's hard to know whether having the time to work on them would have helped your score.
If, however, you were able to at least answer the last four verbal questions (even incorrectly), I think you could very well have seen at least some increase because the GMAC makes it clear that guessing and getting them all wrong is better than leaving any blank. Since you would have had a 20% chance of guessing correctly on each question, you might expect to have gotten one out of four correct with pure guesses. I would guess that together those two effects could have raised your score 10-20 points.
If you actually had the time to consider each of the last four verbal questions and if you could keep up your high success rate - perhaps only getting one incorrect out of four - then I think you would see a more significant increase. I would guess that the difference could have been 20-40 points. To re-balance your timing, however, would require that you take about 8 minutes to answer the last four questions. To pull 8 minutes from the other 37 questions would require shaving 13 seconds from each on average. Of course, this in turn would have made it more difficult for you to achieve your high success rate on those first 37 questions, so you may have missed a few more.
One of the best discussions of scoring details I've seen is "The GMAT Uncovered," which is a free PDF available at
https://www.manhattangmat.com/Store.cfm. In particular, see pages 18-23.
Since you are already at 700+ on practice exams, I recommend the following to improve your speed on the verbal section:
1. Focus on improving your SC skills and target 90 seconds or less per SC question
2. Minimize and preferably eliminate note-taking on RC
3. Cultivate your ability to absorb information and think critically when you are focused 100% on what you're reading. The GMAT requires a different kind of reading from what we normally do in our daily lives. So when you study, don't slog through problems for 3 or 4 hours straight. Take breaks every 75 minutes, as you would on the exam, and make sure you're always a focused, "active reader" on verbal questions.
4. If you are not someone who reads very much, then take a page from Nike's playbook and "Just Read." If you read just one 300 page book, you may notice that your reading speed increases appreciably - at least temporarily. Even a 10% improvement can make a significant difference. (In rough terms, 10% of the time on the verbal = 7.5 minutes, which is just about what you'd need for those last four questions.)
There are other strategies that might be relevant based on your particular situation.
Hope this helps. Once again, good luck!
