Im +18, +19 front and rear with 19's and 9.5 front and 10.5" rear...
255 front and 275 rear tire sizes and will go 285 rear next time..
Fits fine as Im stock height with Eibachs on the way to lower 1".....I think it may rub the fender lip if you go really aggressive drop w/o alignment and depends on front tire size..
GT-S fit?:19x9.5 +17 / 19x10.5 +18