Make em throw. We use to load the box with a 6-1 and walk a safety down on the wide side of the field, looked like an offset 6-2. CB and Safeties were athletic enough to keep everything in front of them. Line shifts pre snap, strong slant/weak slant/pinch. Bring a bad attitude with you.
You have team speed...keep gap integrity, shut down middle, and make them bounce it outside and cut em off. RB runs more when he has to go around, keeping them running out of bounds keeps stopping the clock and forces a running team to play your time of possession game.
Worked for us back then. Didn't alow a 100 yd rusher all year and never allowed more than 200 yds in a game.