Level #1 on the JB4 does nothing, you are running stock.
Level #2 requires 91 octane
Level #3 requires 93 octane
Level #4 requires E85, or 93 octane or better.
If you add the airbox lid with larger MAF tubes you'll get a Level #5 custom tune to adjust things for that extra airflow.
Order a 54 gal drum of Sunoco EVO 10 105 Octane Race Fuel for about $750, plus about $100 for shipping and you're at $850 for 54 gal, or $15/gal.
10 gallons of your 91 octane pump gas plus 2 gallons of this ,gives you the 93 octane not otherwise available to you. And much more if you want it! This is Sunoco's highest octane unleaded product.
Upgraded exhaust might help some, but is not needed. You will feel big gains without it.