Invest in MSAR and look at 90th percentile MCAT stats for lower tier schools. If you have a 4.0/37 I wouldn't use safeties on schools where your MCAT is above that school's 90th percentile.
Just as a rough estimate here might be some good "safeties": Hofstra, Miami, Tulane, Tufts, Saint Louis, Jefferson. I believe all of these schools have MCAT medians of at least 33 so you aren't that high above their median like you would be at a school such as GW or Penn State.
If you are an Illinois resident you have a solid range of lower tiers. U of I, Rush, Loyola and Rosalind all show at least some IS bias. You don't need that many more lower tiers being from there.