I can run high 9.70's @139 in a car that weighs 3970 on a 9" x 30" Hoosier radial with caltracs and split leaf mono springs - I also run strange double adjustable shocks at all four corners - the shocks have helped tremendously with consistency and tuning to track conditions . - the car must dead hook or it will spin - 60' is usually around a 1.40 - I run 21.5 lbs of air and watch that very closely as it if goes to 23 it can spin - hence it's an elephant on roller skates! I am thinking of changing to the pro-bracket radials this coming year - I Like what I see so far. Radials take some thought and tuning of the chassis but they work very well - yeah it would be easy to go to a ladder bar or four link and put a bigger tire under it - but then that would take all the fun away!