what do you mean when you say "We matched them up to the old springs"?
They should have come with some indication if they were for the front or back. The spring rate is probably printed on them somewhere. Did you check for that and make sure the matched pairs went front back, not left right? I'm guessing you didn't look, or you didn't find any spring rate printed on them, or you wouldn't have posted. Take the wheel off and check the front and see if you find any printing on there.