so i've already gone -1/ stock, it helped a lot going on down in the front but i want a lil more, i'm thinking about going +4 in the rear, its on a '90 ninja zx-6, re-jetted, micron exhaust, k&n filter. any opinions? its not for top end, i don't care if it tops at 120 i never go that fast anyways i'd rather it stand up that top out.