probably about 1" rear and 1 1/4" front. every car is a bit different.
zim can chime in here. i sent him two sets of springs... one set i know was lost but the second... well, at this point i'm selling these i got in a few weeks ago and sending him the money. i am doing this on good faith. i buy and sell parts often and have an outstanding reputation. i moderate the classifieds on a texas
mustang club site and this site. i understand your line of questioning though, that's what the "seller rating" is for.