I have had a custom set of Alcan springs on my xj for quite some time from a comp XJ so the spring rate sucks if i want to put any thing in the back like people with just me it runs sweet so i am thinking of looking for some progressive rate springs but i havent seen much out there Alcan has said in the past why run a 11 or more leaf pack when you can do the same thing with a 6 leaf pack i dont like their answer.