mine is a double cab, non-trd,4x4. 86k miles. i carry heavy loads often. with the age and hard use, it seems that my suspension (mainly the rear) is getting tired. i dont want a lift yet. an inch wouldnt bother me though. my question is what should i replace it with? i've been thinking about going with trd spec suspension. what about same year model tundra susp.? what would that do to my truck? or should i just replace it with new stock susp.? and , would i need new leafs and shocks or just shocks? please let me know your experience or knowledge. thanks.