this upgrade pretains to the older style frames , when I bought my 2007 street glide I was never quiet happy with the ride of this bike .my o4 classic had a much nicer ride , the street glide just does not give you a true HD touring ride like the other models RK/ultra/ claasic or standard. because of the shorter shocks you loose some comfort . I had enough of the substandard SG ride and bought a set of progressive 440 ias shocks ,install took all but 30 min , after 2 weeks of riding with them I can say ther is a vast improvement on comfort ,the bike handles (cornering) with great improvement ,the high speed wobble at high rates of speed has become much less ,it comes out of the wobble much quicker without a need to back off the throttle, I also intentionally did this upgrade knowing my rear tire had no life left maybe 1000ths tread left on this tire, being very happy with these results I road another week or so to get a real good feel for the changes in handling and comfort and I road hard and fast everywhere aprox 600 miles , Now being quiet happy with the progressive shock up grade I turned my attention toward the wobble at high speed cornering that occurs , So I ordered and installed the progressive touring link stablelizer , Know I have found in the past with 2 of the touring bikes I have owned the wobble would get worse and more prounounced as the tire wear increased , on a new tire the wobble would not really start occuring till the tire had about 1500 miles on it,then from there the wobble would get more pronounced (violent) as tire wear occurs. this is why I choose to do both of these upgrades with a rear tire that should have been changed 1000 miles ago . The touring link stabilizer kit is another 30 min easy install as long as your bike has correct engine alighnment and you have exhaust clearance . Soo here is what I found the first road test showed little improvement in the high speed wobble but, after about 50 miles I detected improvement ,So there is a breakin period on the stabilizer kit , after putting on another 400 miles on the bike all I can say no wobble superb handling at high speed cornering over 80 mph all this on a rear tire that has well exceeded its life .....So now Im off to change the tire and finally enjoy my SG ride and handling on the open road.