The sportsman categories have a designated number of entries allotted at national events.
For Stock and SS, I believe Indy is the only race where that allotment is over 128 cars.
Since they only run 128 cars in those classes, you’re qualifying just to make the show.

At most national events the allotment for Stock and SS is usually 60-80 cars.
Since that’s less than 128....... everyone gets in.......whether you can run the index or not.