I thought I would post this for anyone looking for information on this particular combination as before purchasing I could not find any information on this.
The Ridgid Drill that I am talking about is the one with the 700 in-lbs. of torque. I had purchased this drill last summer planning use it to run a K-Drill for ice fishing. At the time of purchase I did not realize that it didn't meet K-Drill's specifications.
This combination does not meet K-Drill specifications (minimum of 725 in-lbs.) It also does not work in the real world. Drill would turn the 8" K-Drill and start cutting a hole but get bogged down and cut-out. I could eventually get through the ice with it (about 15") but it would cut out multiple times on the way through. Not only was this annoying but I don't imagine it was very good for the drill.
I ended up buying the Milwaukee with 1200 in-lbs. of torque. This combination shreds through the ice and is super light.
I do not know if the Ridgid would have the torque to run the 6" K-Drill but it definitely was not sufficient for the 8".
Hopefully I just saved one of you some money or frustration.