What could help is don't worry about finishing entire sections. It's better to get 95%-100% accuracy on the questions you attempt and guess on the rest; with a 147, you are probably getting about -12/-13 per section. Focus on finishing about 14-15 questions per section and making sure that your accuracy on those 15 is about 95% to 100%. The remainders just guess.... that way you are guaranteed at worst -12/-13 (if all the guesses are incorrect) and you will likely get maybe 4 of the guesses correct. That should bring you to around a -9 per section which should be about a 153. This will give you much higher odds statistically than just doing all 25-27 questions but with a lower accuracy.