there is the oe crank pulley along with a custom made one..through group purchase. i do not have an extra custom. JW might have one. the difference in size isnt so much that its gonna prevent ur other components from performing correctly. ur alternator will not have any issues charging the battery...ur a/c compressor is still going to be working as LONG as u get the CORRECT belt....it does not slow down enough to make that much of a difference.