Curious as to whether this can be done safely or not (this is my first lifted truck, so no real prior experience). My '87 has between 6-8" of lift (previous owner wasn't sure, as he had bought it himself lifted), but the rear end sags about 1-1.5". I know the rear has blocks, not sure on whether it's still got stock leaf packs or re-arched ones. Can the BWP 1" leaf lift block deal be used on the rear, with lift blocks already in place? Since the leaf block actually bolts into the leaf pack, I'd assume it would be ok because I wouldn't be adding any "sliding" parts to the left, but I wasn't sure.