[1986Silverado]

When I got my truck I noticed the rear springs only had 3 leafs......and also noticed that the LMC catalog only goes down to a 4 leaf spring. My questions are this......Would it be safe to tow with 3 springs?(I'm guessing not). Also I want to lower the truck but with the 3 springs gone it makes it kinda akward to do it right. It sits at 31 inches in the rear now. And last one..I want to be able to tow/haul with this truck some, so could I get a old spring and remove the leaf or leafs that I need and put them in mine? And how do you do that(never took a leaf spring apart!