Not sure how you do the hi idle mod on the fords but you can do them on the chevy's so that in the morning when you start the truck you can bump the idle up with the cruise control. High idle is used in the winter for warming the truck up. Diesel trucks really don't like cold so the high idle is nice i haven't done mine yet i use my foot when i'm sitting in it The newer chevy's i know used to do this on there own a buddies 05 duramax does its kind of cool while its sitting there it sounds like a jet getting ready for take off