Seeing as drag radials are named specifically for drag racing, wouldn't it make sense that they're what you should use for drag racing?

Anyway, depending on whose DOT-legal drag radial and whose DOT-legal road race or autocross tire you look at, they can be a lot different or almost identical.

For example, the Nitto NT555R drag radial and the Toyo Proxes RA-1 road race/autocross tire have the exact same tread patten and rubber compound (Toyo and Nitto are the same company). The main difference between them is sidewall construction. The NT555R has a kind of mushy sidewall that helps it hook up better onlaunches, and the RA-1 has a stiff sidewall to keep the tread planted in cornering.