I was told by the PO that the lift on my 78FJ40 was a 3" BD kit. Those were some of the stiffest springs and they beat the crap out of me. I replaced them with some 4" Skyjackers that I got on the cheap and they are MUCH softer riding. I can't confirm that what I had were BD but that is what I was told. If I were going to buy new, HellCreek is where I would be buying from. Great company, great price and semi-local to me. I know several guys running their stuff and they all love it.