I had been dealing with the random vibes at 70-75mph for 10 months,7500 miles.Put Bilsteins on the 4 corners as well,and it did improve the ride quite a bit,but didn't solve the vibes,So between the vibes,clunking leaf springs,nasty A/C smell at start up,and feeling every little bump on the highways( I live in Arlington and drive I-20 and 360 everyday) I traded it for late model Tahoe LTZ, Quality built vehicle,nice ride,still have room to throw stuff in the back.Truck depreciated $5000 in 10 mo.s,oh well,Love the Tahoe.