I know too many students who has ugpa good enough for med school absolutely ruin their chances by doing an SMP that they did NOT need to do.
skip the smp, it ain't for students like you, and just spend the time/money killing the MCAT. even if you do well in the SMP, you STILL need to retake the MCAT anyways, so why bother?
an mcat below 500 indicates content issues.