I use 23x5 goodyear front runners on the protree car, with 14x32 bias slicks, firestone f560 165x15 radials on the other car with 315/65x15 dr pros or hoosier quick time pro bias, (tallest that will fit with fenderwell headers, and replaced the 165x15s (4"rim)with tall 235/75x15s on the full tree car (7" rim) to slow reaction time a bit. (To many red lights) Been running radials with bias slicks for a LONG time.
