Welcome szyg6h. 
Do your blades look like the ones pictured below I found on DR's website?
DR® Power Equipment - Tow Behind Field and Brush Mower Accessories
Looking at the blades there are no "wings" on the backside of them. The wings seen on finish mower blades are what give the lift action. Also the design of the deck for finish mowers has more of a tunnel shape to aid and direct airflow.
You might be able to find some finish mower blades for it with wings to create some lift. But it might reduce it's ability to plow through tall grass and brush which finish mowers don't normally have to do.
Do your blades look like the ones pictured below I found on DR's website?

DR® Power Equipment - Tow Behind Field and Brush Mower Accessories
Looking at the blades there are no "wings" on the backside of them. The wings seen on finish mower blades are what give the lift action. Also the design of the deck for finish mowers has more of a tunnel shape to aid and direct airflow.
You might be able to find some finish mower blades for it with wings to create some lift. But it might reduce it's ability to plow through tall grass and brush which finish mowers don't normally have to do.