Ok I have a 02 sierra rcsb it currently has a 6" rear drop but I'll be dropping it to 8" real soon. I've read about people using air shocks for dodge caravans chevy ventures and nissan frontiers. Which do I need to go with? My truck does not have shock extenders and I need air shocks cause I also put my 4 wheeler in the bed when I go out to ride and that's the only load it really sees. Thanks in advance