Welcome Technerd,
You will find great resources to guide you through your conversion. Lots of great people happy to share their knowledge and experience.
That said, use a little caution and don't blindly follow advice without doing your own due diligence.
Trust me.......
Link:
RV Driver's License Requirements
Link:
RV Driver's License Requirements | RV Miles
Illinois driver's licenses are classified by the GVWR of a vehicle (and any towed vehicles):
Class A —
Any combination of motor vehicles with a GCWR of 26,001 pounds or more,
providing the GVWR of the vehicle being towed is in excess of 10,000 pounds. Also allows
for operation of Class B, C and D vehicles.
Class B —
Any single motor vehicle with a GCWR of 26,001 pounds or more or any such
vehicle towing another not in excess of 10,000 pounds. Also allows for operation of Class
C and D vehicles.
Class C —
Any motor vehicle with a GVWR of more than 16,000 pounds, but less than
26,001 pounds or any such vehicle towing another not in excess of 10,000 pounds. Also
allows for operation of Class D vehicles.
Class D —
Any motor vehicle with a GVWR of 16,000 pounds or less. Does not include
A. B, C, L or M vehicles