I've got a set of progressive 412 rear shocks off of my 1995 Ultra classic. I want to install them on my 2010 ultra, to lower it an inch. Any reason they won't fit on the 2010? The original air shocks from the 2010 and 1995 look identical. Progressive web site says the 412's for a 2010 are part number 412-4074C and for a 1995 it's 412-4006C. I've measured everything on both bikes and can't find any difference. Anyone know why it's two different part numbers? Thanks.