92 K1500 Silverado 4x4 lift kit issue.
 

I drive a 92' K1500 1/2 ton 4x4 P/U that I bought from a buddy. It came with a 3" in body lift, which doesn't bother me as much, but i've wanted to put a 4 inch suspension lift on it. Here's my problem.. I can't FIND one. Anybody also drive one of these trucks and know where to buy a 4" suspension kit? I'm quite flustered trying to find one.