How important are SAT II scores?

in comparison to SAT scores? I did pretty well on my regular SAT (2210), however, I did so-so on subject tests (670 Math II and 720 Chemistry). Ordinarily I would consider those decent, but I'm only in the 54th percentile for math and 69th for Chem, so how heavily weighted are the subject tests in comparison to regular SAT at a competitive school? My GPA is solid (somewhere around 4.2 weighted) and I do a fair amount of curriculars, so I'm a fair candidate but by no means a shoe-in. Should I retake Math II and shoot for a higher score? I'm also considering taking lit