Disregard, I realize now that it is a setting for the prep tests not a setting for the drill sets. > @ said:

I just took an LR drills set and saw that there were questions from PT66 in my drill set. I only want questions from early tests but I don't see where the ability to use the "Simulate Modern" function is on the create drill set page. What am I missing?

I just took an LR drills set and saw that there were questions from PT66 in my drill set. I only want questions from early tests but I don't see where the ability to use the "Simulate Modern" function is on the create drill set page. What am I missing?