I'm away at work for 5 more days, I'll try and remember to measure and get back to you. I'm guessing you'll need the 2.5", although I left the upper strut spacers off, so I probably didn't get the full 2.5" level in the front. I highly recommend these tires and setup. I love the looks and the improved traction. I live in AK so I do a lot of winter driving obviously. I work in the oilfield at the north slope of AK and most of our F250's up here run these tires for good reason.