I run a stock type setup, and I've had a best sixty of 1.69, so far, and it will go down even further. I've got plenty of motor, too! I run the firmer Bilsteins all around, stock springs, Hotchkis front and rear swaybars, and upper and lower trailing arms.
Good track prep, and Hoosier 15X11.5 QTP's give me consistent low 1.70's, every time out. Suspension work really isn't necessary, with good tires, and a good track, unless you have a monster motor, and a monster shot of juice! HTH