Hi m94m,
To raise a 490 to a 700+, you will have to make significant improvements to how you handle BOTH the Quant and Verbal sections - and all of that work will likely take at least another 3 months of consistent, guided study. Based on the timeframe that you've described, you'll have just 1.5 to 2 months though - and that will likely not be enough time. The type of 'cramming' that you're talking about (studying "all day" during that time period) rarely leads to great results and actually increases the chances of 'burnout' before Test Day (and that is something that you want to avoid).
Is there a reason why you're limiting your studies to such a relatively short period of time?
1) When are you planning to apply to Business School?
2) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich