Just wondering about DOT-approved tires and their speed ratings... I believe those numbers (S=112 mph, H=130, V=149, etc.) are for sustained operation at those speeds. How important are those ratings on the strip, where they might be exceeded for a couple of seconds at most? Do tires like the ET Street even have a speed rating?

At the drag strip speed ratings don't mean a thing. Most drag radials except Nittos don't have a speed rating. Strangly though the ETCA allows drag radials for most classes that are up in the V and Z area. When I ran the Maxton Mile I only needed S rated tires since I wasn't going over 150 MPH. I don't believe bias ply tires have any speed ratings.