Making my race car slightly less of a race car

do what you need to do to make it "street" , and those slicks are huge for a low 12 second car. you will gain around 100 pounds=1 tenth of a second slower. a 11" X 28" will be lighter rotating weight=1 tenth quicker. my Duster weighs 3040 with 340, A833 iron 4 speed, steel bellhousing, 8.75 rear, aluminum intake, 2.5" mufflers, 2 stock bucket seats, carpet, roll bar, horn, all lights work, stock glass and sheetmetal and bumpers, small battery, manual drum brakes, manual steering , street driven - sometimes to the track - 100 miles each way. 11.7 at 115