Not sure upper stableloads are right for me (UPDATED)

Use a hose clamp around the wedge and lower spring. I cannot say if this is the best way to do it, but it will allow you to drive around a little and see the difference. Since mine was pre-drilled, I rand around with blocks secured by a short lag bolt until I was convinced to buy to the lower StableLoads (like you, I started with the uppers first).