Scored a 740 with a low quant score, should I retake?

Now, before you think I'm crazy, hear me out.

I gave my first GMAT earlier today and scored a 740, Q47 V45. While this may at first glance seem like a great score, I feel very uneasy about that quant score. Especially given that my undergraduate GPA is quite appalling and especially in quant courses, with multiple F's even.

On the test I found the quant section relatively easy but I think I made a few careless mistakes here and there. In addition, I also screwed up the timing towards the end and had to rush through the last two questions, most likely getting them wrong.

In terms of potential for improvement, I think I may be able to get a better score on Quant, but that being said, my highest score on a GMATPrep mock was 48. Do think I can push it a little more though. Verbal on the other hand, I'm definitely satisfied by.

I do not plan on applying this year and am instead aiming to apply next year. That gives me around 11 months before I need to start focusing on the other parts of the application including building an alternative transcript, making a career move and bolstering my extra-curriculars. My question is, do i spent a month of that time reappearing for the GMAT or should I leave the GMAT alone and focus on the other stuff? Also, the schools I'm looking to apply to are top 15 American programs

Any advice would be much appreciated.