Originally Posted by JEFASOLD

If you go with the smaller SC pulley, you don't have increased speed of the pulley and ancillary stuff, water pump, idler, alternator, with a larger crank pulley you do have increased speed of belt, idler, water pump, etc. The best solution is stacked setup, SC 70mm, crank 181mm but you need larger capacity fuel pump, plus fuel pressure regulator and possibly larger injectors. I have the above setup, plus colder plugs, manis, DCAI, cooling mods, custom exhaust and Inmotion tune.