I am pretty sure he is asking specifically for Olin....or else why would he post it here? He also did not ask which schools he should apply to......
Back to OP, you should definitely retake the GMAT. 670 is, just to be completely honest, simply not enough for Olin, especially if you are from an over-represented group that traditionally has insanely high GMAT score, not to mention Olin's average is just shy of 700. No one knows what your GPA means, so please convert it to a 4.0 scale so people can understand it.