increase spring rate or fix the unloading problem. some people are cheap asses though.
I say replace some leafs in your packs with some stiffer stuff. try lowering that POS down at the same time. shocks are just a bandaid and you will wear them out/ blow them out if they are doing all the motion control in a cornering/sidehill situation. this might have to do with suspension setup. if you have minimal uptravel, and alot of downtravel your suspension could be unloading and causeing a "raising, or lifting" sensation.
Its a package deal, everything works together and against each other. your high COG combined with relatively narrow width and inboard ish springs. post a picture of this turd so i can pick it apart :flipoff:
All shocks have different valving as well. BBCS that Hot karla mentioned, have different coil and leaf spring valving in them when ordered. possible the 5150's you had were valved VERY incorrectly for your application.