[Tx Firefighter]

I've had my rear leaf springs de-arched before at a spring shop. They charged under 100 bucks and lowered them exactly what I asked for. Look in the phone book under "truck spring shops". Think Peterbilt, not Chevrolet...

Also, measure the truck exactly when deciding how much to lower it. I did my Blazer, and one spring had sagged more than the other over the years. They wound up de-arching one spring about 3/4 of an inch more than the other to level the truck out, side to side. Just mark the springs when you remove them and tell the guys which needs to dropped more.