Background Check - comparing unofficial to official transcripts

Hey guys, so I messed up. I'm a senior in college, and I recently received a full time offer from an investment firm. This has been my dream job for as long as I can remember, but due to personal issues it has been very difficult to keep my GPA up.

The problem is, the minimum GPA for the job was a 3.5, but I only had a 3.35. I put 3.5 on my resume and changed two grades on my unofficial transcript (I know), because without it, I wouldn't have even gotten an interview.

I am not sure, but I believe the firm will ask for my official transcript at some point through a background check firm. I am confident I can push up my GPA from a 3.35 to at least a 3.45 by the time I graduate (fulfilling the minimum 3.5 requirement).

However, my question is, will the background check firm just compare the official transcript to my resume GPA, or will they literally compare my unofficial transcript that I turned in to my official transcript? To be clear, I submitted my unofficial transcript to the firm itself, but I believe the official one will be sent to a background check company.